*Thank you to Dutton and NetGalley for an ARC in exchange for my honest review*

What a fun mystery! Full of puzzles, secrets, and deception, this book will keep you guessing until the very end. I loved the references to gaming, puzzles, and classic mysteries. It's clear that Kelly Mullen has a real passion for the genre. Murderscape is totally a game that I would play, as a fan of all things Nancy Drew and riddles. I've always wanted to visit Mackinac Island, so it was cool seeing a book set there! It also was a surprisingly perfect environment to induce that "snowed-in isolation" that locked room mysteries are known for. This is a book that I think would naturally lend itself to a series, but can also stand on its own if that isn't pursued.

This Is Not a Game is a locked-room mystery that brings a quirky twist to the classic murder-at-a-mansion setup. Widow Mimi lives on idyllic Mackinac Island where cars are not allowed and a Gibson with three onions at the witching hour is compulsory. Her granddaughter, Addie, is getting over the heartbreak of her fiancé, Brian, dumping her and cutting her out of the deal for the brilliantly successful video game, Murderscape, they invented together. The two women, grieving, prickly, and fiercely independent in their own ways, are thrown into a weekend charity party gone murderously wrong.

With a blizzard trapping them in a remote estate and bodies beginning to pile up, Mimi and Addie become an unlikely detective duo, using their respective talents: Mimi’s puzzle-solving obsession and Addie’s game-designing logic to try to unmask the killer before time runs out.

While the intergenerational sleuthing angle is a refreshing concept, I found This Is Not a Game to be a fairly by-the-numbers amateur sleuth mystery. The murder plot unfolds in familiar beats, and the “trapped in a mansion during a snowstorm” setup, though atmospheric, doesn’t bring anything particularly new to the table. For me, the most enjoyable part was the banter between Mimi and Addie.

Ultimately, while charming in premise, this debut didn’t quite stick the landing. Fans of cozy mysteries and murder puzzle tropes may find enough to enjoy here, especially if they’re drawn to books like Knives Out or The Thursday Murder Club. But for readers hoping for a fresh take or an unpredictable twist, this one plays it a little too safe.

Thank you to the publisher and NetGalley for an advanced copy of this book.

For some reason I had trouble getting into this book. There was something about the grandmother / granddaughter relationship that was off-putting. They were sort of mean to each other which is not what I was expecting. Listening to the audiobook and having someone say the things out loud might have exasperated that fact too. It ended up being a decent mystery and I am glad I finished the book, but the relationship made it hard to get into the mystery solving. If there was a second book, and having their relationship start off at a better point, I would read it. Probably.

**Thank you to Dutton Books and NetGalley for the eARC of this locked-room thriller!**

I adore escape rooms and enjoy locked room thrillers so much. Throw in a winter storm and some silly dialogue and I am in there!!

The granddaughter / grandmother crime solving duo in this book were so enjoyable to read and this is one I absolutely flew through. Settle down with a nice cup of tea on a rainy day and crush through this one!!

Mimi can't stand seeing her grand daughter, Addie, suffer through a broken heart. When the chance to attend a charity event weekend in an isolated mansion. When a storm rolls in and the hostess is found dead, the mystery becomes an exercise in solving the murder without becoming the next victim. This Grandmother and Grand daughter duo make excellent investigative partners. This may be Kelly Mullen's debut, but she's penned a winner with Mimi and Addie.

Thank you NetGalley! This book had some of my favorite aspects of a who dunnit/ locked room type mystery. I loved that the characters solving said mystery were different than the usual detectives. This is a great book if you’re looking for a break from more graphic thrillers.

Kelly Mullen’s This Is Not a Game is a twisty and brilliantly crafted thriller that blends family drama, dark secrets, and murder into a captivating whodunit. Widow Mimi and her estranged granddaughter Addie make for an unlikely sleuthing duo, but their dynamic is what truly makes this story shine. Their strained relationship adds depth to the tension, as personal growth intertwines with the unfolding mystery.

Set on the picturesque yet haunting Mackinac Island, the novel’s stormy night in a trapped mansion perfectly sets the stage for suspense and intrigue. Mullen excels in creating a cast of eccentric and flawed characters—each brimming with secrets—that keeps you guessing who’s behind the chaos. The twisty plot, from the salacious blackmail to the high-stakes murders, feels fresh and unpredictable.

With its clever balance of dark humor and chilling thrills, This Is Not a Game is a must-read for fans of mysteries with sharp dialogue, richly drawn characters, and suspense that keeps you hooked until the last page. Mimi and Addie’s journey is every bit as heart-pounding as it is emotionally rewarding.

Mimi loves her quiet life on Mackinac Island. Sure, during the summer, their small Michigan island is overrun with tourists, but once the temperatures fall and the snow hits the forecast, it’s a quiet life. She had bought a small house with the help of her late husband’s life insurance, and Mimi is happy to live there alone, with her nightly Gibsons, her bridge club, and her snowmobile named Joan Rivers.

But then she gets invited to an event at the home of a local celebrity. Jane Ireland is a descendant from an old money family, and she is well known for her outrageous lifestyle. Her current boyfriend is also her son-in-law Matthew, which has caused quite a stir. She is having a charity auction, and Mimi is invited. Mimi is generally not invited to things like this, but this time she can’t miss it. Really, she can’t miss it, because she is being blackmailed. She has to go and bid an outrageous amount on a certain piece in the auction, or her worst secret will come out. Mimi knows she has to go, but she doesn’t have to go alone. She emails her granddaughter for help.

Addie is a game developer who lives in Chicago. She and her boyfriend had developed am interactive murder mystery game called Murderscape, which is hugely popular. Brian had gone on to propose to her, and then recently, to dump her. Now, he’s taken sole ownership of the company that owns Murderscape as well as full credit for the game, so when Microsoft made a lucrative offer for the company, he also took sole ownership of the check they wrote him. Addie has spent her time since leaving working her day job at an ad agency, watching Dateline, and considering hiring an attorney and getting what is due to all her hard work on the game.

But when Addie gets the email from Mimi, she doesn’t hesitate before heading to Mackinac Island to help her. Mimi doesn’t tell her about being blackmailed, but Addie agrees to go to the party with her. But things don’t go quite how they expect. Mimi and Addie arrive at the party and get their cocktails, waiting for the auction to start. When it does, Mimi bids on what she’s been told to, but the price is far more than she was informed it would be. Addie is stunned, and they step outside so Mimi can have a cigarette. She explains to Addie that she’s being blackmailed. And when they go back inside, they find out that Jane has been murdered.

The snowstorm has picked up, making it impossible for anyone to get to the island, and the local police officer on duty went home sick, to the mainland. No police can get to the island that night, and no one cam leave the Ireland home. So whoever killed Jane is stuck there with them. Mimi is a puzzle fanatic, and Addie has always loved studying crime. Mimi believes that they have the best chance of figuring out who the killer is, and she convinces Addie to investigate with her. But as the night goes on, more crimes are revealed. Sime items from the auction and personal items have gone missing. Matthew is also killed. And there’s the fact that Mimi probably isn’t the only person at the auction who was there because of blackmail. Addie uses all her knowledge from Murderscape and from years of Dateline to create a murder notebook and keep track of everything they know.

But the longer they’re all there, the more danger they’re in. And as Addie and Mimi go around questioning alibis and trying to suss out secrets, the bigger the targets they are painting on themselves. Will they be able to survive the storm and find a killer before it’s too late?

This Is Not a Game is a twisty thriller where everyone has secrets, everyone is telling lies, and it’s up to Harriet the Spy and Jessica Fletcher to solve the mystery. There is a stylish party, a lot of cocktails, and a locked-room mystery where the lock is an actual drawbridge that those inside can’t open without the code known only to the murder victims. This mystery is stacked with interesting characters, who all seem to be pretending to be someone different than who they are, making the plot shift from side to side.

I really enjoyed This Is Not a Game, especially the ending, which is satisfying in the best way. I liked Mimi and Addie a lot, so following them around as they try to solve a mystery was lots of fun. There were moments I had some trouble remembering who was who in the large cast of party goers, but mostly, I just liked this story so much.

Egalleys for This Is Not a Game were provided by Dutton through NetGalley, with many thanks, but the opinions are mine.

A Roaring 20s themed auction with a side of blackmail. A snowstorm in the off-season on Mackinac Isalnd. A dead body (or more?). Sounds like the making of a fantastic who dunnit.

Mimi is a saucy septuagenarian with a few secrets in her past and a snowmobile named Joan Rivers. Her granddaughter, Addie, is the co-creator of a popular murder mystery video game whose ex is moving on and taking all the credit (and cash) for the game. Together they'll need to figure out who is the murder and how to get off this island.

I was hoping for some twists similar to And Then There Were None or at least some unexpected actions or alliances. I wanted more connection between Mimi and Addie. I also wanted some resolution on the Brian situation besides just ignoring his phone call. A few other things I wanted that could be spoilers: <spoiler>I really wanted someone to have faked their death and masterminded this whole game. Or at least have Alexandra have a hand in the escapades. Why was she off the page? Why was she so blase about her husband dating HER MOTHER?</spoiler>

But I would read a sequel. Maybe Mimi can visit Addie in Chicago.

Thank you Random House Publishing Group - Ballantine | Ballantine Books and NetGalley for the advance reader copy. I am required by law to disclose this

#ThisIsNotaGame #NetGalley

Rosemary "Mimi" Louise MacLaine knows her place and is assured in it. She's been on the island of Mackinac for a very long time and knows how her life will run. At least until a mysterious invitation appears on her doorstep. It's an invitation... and an order. Unless she comes to the party and bids on (and wins) a specific item, her dirty secrets will be revealed. It is the latter direction that has Mimi reaching out to her granddaughter, Addie for the first time in months.
Addie is fighting her ex-boyfriend for recognition that she deserves on the massively hit video game that she helped him put together. She argues with her grandmother over that same man and now she's been dumped and pushed out of the company. But her normally unemotional grandmother has reached out with an olive branch and Addie is willing to try.
The two attend the party. It's hosted at the mansion of a woman who is infamous for cavorting with the man her daughter is still married to. And it's an eclecticc group of people who are gathered, including one who Addie is sure she knows under another name. Of course, there is a murder. And a snowstorm. So it's up to Mimi and Addie to figure out what happened.
There was a little too much going on for me, especially at the end, but I generally enjoyed this story and look forward to reading more by the author.

Three and a half stars
This book comes out April 8, 2025
ARC kindly provided by PENGUIN GROUP Dutton and NetGalley
Opinons are my own

In this book, 70-something widow Mimi lives on Mackinac Island in Michigan. When she is invited to a party by a neighbor she hates - complete with blackmail demand - she invites her granddaughter Addie to come with her for moral support. And when their hostess turns up dead and a snowstorm traps them all in the house - well, it’s a good thing that Addie is the designer of a popular online murder mystery game, as grandmother and grandaughter team up to try to solve the murder themselves.

This was a fun, cozy-ish locked room mystery - kind of like a book version of the movie Clue. All the little meta nods to it being a live action video game while Addie works through clues were entertaining too, even to someone like me who doesn’t play such games. An enjoyable debut and I’d definitely read more from Kelly Mullen.

Grandmother Mimi, and granddaughter Addie attend a lavish party/auction at a mansion, and things quickly turn south when their host is murdered. What ensues is a fabulous locked room mystery! The mansion includes a drawbridge, and secret passages, and several murder suspects. With Addie's gaming background, and Mimi's tenacity, this grandma/granddaughter duo is giving Poirot a run for his money! I really enjoyed the characters, the setting, the pace, and the writing in general. I would love to see Mimi and Addie in action again!

I needed a palate cleanser after some heavier thrillers and this came at the perfect time. Mimi and Addie were a great duo who played well off each other. Addie having a background with detective stories was a nice touch that helped to make the amateur sleuthing more believable. I loved the island setting which added to the locked room nature of this one. I have added Mackinac Island to my list of places to visit but during the summer so I don’t get stuck in a snow storm.

Thank you Dutton Books and NetGalley for the free book.

This was such a fun locked-room murder mystery reminiscent of Clue, featuring a grandmother / granddaughter duo as the detectives.

Blackmailed into attending a party at her rich neighbor’s house, Mimi invites her estranged granddaughter Addie to attend with her. During the party, the hostess is murdered and grandmother and granddaughter must use their combined skills to solve the murder before it’s too late.

This is Not a Game is full of fascinating and eclectic characters, nods to classic mysteries, and hilarious banter between Mimi and Addie. I loved watching them solve the puzzles and put together clues.

I love cozy mysteries with quirky old characters. This mystery was fun and entertaining.
Mimi, a 77 year old Widow, is witty, funny, smart at solving puzzles, and lives her life her own way. She prefers a Gibson martini with three onions, specifically 🍸when she got an unusual blackmailing invitation from egocentric Jane Ireland for a charity auction event at her glamorous Manor, she invited her estranged granddaughter, Addie.
Addie had developed a super successful game Murderscape with her fiance, but he cheated her and cut her from the profiting deal and dumped her.
They both met several eccentric guests on the day of the event. Suddenly, Jane got murdered and everyone was trapped in the manor surrounded by a moat and raging snowstorms outside. Everyone is connected to Jane one way or another and appears suspicious. With no help from outside, it's up to grandmother and granddaughter duo to solve the crime and uncover the killer.
They both are amateur sleuths with whip smart mystery solving skills to uncover the mystery.
I love their relationship, their constant banter and bickering, and sarcastic dialogues, but they both deeply care for each other.
Now, starts a game of lies, secrets, conspiracy theories, and jealousy. The author leaves little clues throughout but, still I couldn’t guess.
It was fun, light, and easy read with not one but two adorable Dachshunds. I am looking forward to reading more adventures of Mimi and Addie, perfect duo.
Thanks to @Netgalley @duttonbooks and the author for providing the eARC.

Thank you so much to Dutton Books for the gifted ARC!

I am the biggest cozy mystery fan, so I was so excited for this one!

While the cover sold me and the synopsis drew me in, I just never found myself wanting to pick this one up. It was too slow of a start for me and I struggled to care what happened to the characters.

Overall, good concept but not one that I will remember.

In Kelly Mullen's debut novel, This Is Not A Game, estranged granddaughter and video game designer Addie is reluctantly pulled into a lavish charity auction on Mackinac Island by her quirky grandmother Mimi. When the host is suddenly murdered and a snowstorm traps everyone inside a mansion surrounded by a moat, the duo must combine Mimi's love for puzzles with Addie's game-solving skills to uncover a killer among the eccentric guests before they become the next victims in a deadly real-life mystery.

Readers who enjoy locked room mysteries with a touch of humor will find this a delightful read.

Thank you Penguin Group Dutton for providing this book for review consideration via NetGalley. All opinions are my own.

Kelly Mullen is a successful executive producer. She's adding 'author' to her accomplishments, with her debut novel - This is Not a Game.

The first few chapters are very busy. We meet our protagonists -Mimi and Addie. Mimi is Addie’s grandma. No matter their age, they are both keen amateur sleuths. I really enjoyed their relationship, their dialogue and their methods. Addie’s background in video games is unusual, but it really works for this plot.

A stormy night on an island manor, the electric is out… and there’s a body. This is most definitely a locked room mystery. The manor had lots of rooms that have to be found to see them. Secret rooms are one of my favorite finds.

There’s a myriad of supporting characters. One brings that last needed part of a cosy read…..two dachshunds please. There are lots of connections between the guests. Some freely answer questions but others outright lie. Mullen has done a job with parceling out clues. Truthfully? I never guessed who it was until the reveal.

This is a wonderful debut. I wonder if we’re going to see more of Mimi and Abbie?

Thank you @duttonbooks for the free copy. Thank you @prhbooks for the free audiobook!

Sometimes i need a break from my romance reads. Buuut the world is too stressful for me to read thrillers right now so thank the bookish gods for cozy mysteries! 😂

Here’s another one you might want to add to your list!!!
A granddaughter who had created a popular murder mystery game got invited by her estranged grandmother to attend an exclusive party at one of the manors in their tiny island.
Everything was going well until the first dead body showed up…

So basically it’s a murder mystery where you have the following tropes: a spooky manor (yey), stormed in (yey), locked door (yey), whodunnit (yey), fast pacing (YEY) , and short chapters (YEY YEY 😂) it’s like everything I want in a cozy mystery combined in one book!! The best part is, I have zero idea with who the unaliver was!!

I mostly listened to this on audio and omg the narrator was amazing! I was impressed with how she gave life to all these characters!!

Definitely recommend if you’re in the mood for a cozy mystery or if you like Agatha Christie novels! This came out last Tuesday!!!

💭 What’s your favorite drink at a party?
☕️ I’m a margarita/ espresso martini girly

If Clue and an Agatha Christie mystery had a snow-covered love child, it’d be this clever debut. Set on Mackinac Island in a moated mansion (yes, really), this locked-room whodunnit brings blackmail, murder, and a whole cast of quirky suspects to the table. This was an entertaining, cozy-ish mystery with a side of sass. Perfect for fans of Knives Out, Murder at Gull’s Nest, or anyone who loves solving puzzles alongside amateur sleuths.