Artyom panicked and threw the phone across the room. It landed face-up on the rug. From the speakers, he heard a soft, digital chuckle.

“I’m tired of the costumes,” the cat’s voice crackled through the speakers, sounding less like a cartoon and more like a person. “I want to see your room instead.”

One afternoon, Artyom sat at his desk and typed a familiar phrase into his browser: .

Curiosity got the better of him. Artyom tapped the door. The screen flickered black, and a text box appeared: “Do you think everything in life is free, Artyom?”

His heart raced. How did the game know his name? He tried to close the app, but his home button wouldn't respond. The digital Tom walked right up to the front of the screen, his face pressing against the glass as if he were looking out from a window.

Developers like Outfit7 can permanently ban your account for cheating.

While that story is a thriller, downloading mods from unofficial sites carries real risks: Most "modded" APKs contain spyware or trojans.