Blend in or get found.  
Hiders grab the texture of any surface, camouflage their body with it, strike a pose and freeze. 
One Seeker waits in the box, then hunts them down with a shotgun. Guess wrong and you get a cooldown; guess right and the hider joins your side. 
Climb the walls, hold your breath, and don't blink.

Last chameleon standing wins.