Plot

It's Alex's 21st Birthday, but she's stuck at the amusement arcade on a late shift so her friends decide to surprise her, but a masked killer dressed as Mickey Mouse decides to play a game of his own with them which she must survive.

Stuck working the late shift at the amusement park arcade, Alex receives a surprise visit from her friends on her 21st birthday, but their night of fun soon turns into a fight for survival when a killer dressed as Mickey Mouse crashes the party.—unknown

On Alex's 21st birthday, her friends surprise her at the amusement arcade where she works the late shift. However, their celebration is interrupted by a masked killer dressed as Mickey Mouse, who begins a deadly game of cat and mouse. The killer's identity is revealed as Tim Collins, the hypnotized manager, seeking revenge for past grievances. Alex and her friends must use their wits and the arcade's unique environment to outsmart the killer and survive the night.—Anonymous

At a police station, detectives Cole and Marsh attempt to interview Rebecca, a survivor of a recent massacre, so that they can learn who was behind the killing spree and why. Rebecca is reluctant, claiming that she and the detectives will die if she tells them, but eventually gives in and begins to explain what happened.

Some time prior, at an amusement arcade, employees Alex and Jayna are told by their boss Tim Collins that they will have to stay on a late shift due to a last-minute booking. Later, whilst watching Steamboat Willie on a film projector, Tim begins to hear menacing laughter, and a Mickey Mouse mask in a nearby cabinet then begins speaking to him. In a trance, Tim opens the cabinet and puts the mask on.

After Jayna leaves the building, Alex sees Tim wearing the Mickey mask as he chains up one of the exits. Confused and scared, Alex flees, only to stumble upon her boyfriend Marcus and her other friends Ryan, Paul, Jackie, Gemma, Danny, Marie, and Rebecca. It is revealed that the "last-minute booking" was actually arranged by them as a surprise early birthday party for Alex.

As the party gets into full swing, Ryan gathers everyone's phones in a bag and leaves them on the counter. Meanwhile, Paul and Jackie head into the jungle gym to have sex, where Tim/Mickey appears armed with a knife and attacks them. The rest of the group discover that the exits have been chained shut, and their phones have been stolen. After they split up and go looking for Paul and Jackie, Rebecca encounters Mickey, whom is apparently now able to teleport but is easily scared off by flashing lights. Marie also encounters Mickey, who wounds her, but she manages to escape before he can kill her. She informs Alex and Marcus of her encounter, believing Ryan was the one who attacked her since he is nowhere to be found. Alex then discovers that the lights and phone lines are down before she, Marcus and Marie find Paul and Jackie dead.

On Marcus's suggestion, Alex activates the building's fire alarm in order to alert emergency services. Mickey then slits Gemma's throat, teleports into the laser tag arena, slits Rebecca's ankle and kills Danny. Alex sees Jayna returning to the building, but is unable to warn her about Mickey before he teleports behind her and kills her. She returns to find Marcus and Marie, who have found the still-alive Ryan and are interrogating him, making Alex realise that Ryan is innocent before Mickey appears and attacks Ryan. Alex uses a flashlight to distract Mickey as Marcus knocks him down with a baseball bat, but Mickey teleports away before they can finish him off. The survivors realise that they can use Mickey's phobia of light against him, and so lure him into the jungle gym and activate the strobe lights, disorienting Mickey as they beat him down. However, Mickey somehow manages to turn off the strobe lights with telekinesis and teleports away before reappearing behind Alex, decapitating her and disappearing.

Back in the present, the detectives refuse to believe Rebecca's story and leave her locked inside a holding cell before leaving her. In a post-credits scene, Mickey enters the police station, opens the door to Rebecca's cell, and tells her that there are "many people" he wants her to meet, and they are "just getting started". Rebecca stares at Mickey, smiles, and leaves her cell.