Boom (2012)

"Congratulations! You've just found a suitcase full of money on your doorstep! Wait – why would someone leave you a bunch of money? Hmm, what's this note inside the case? "Welcome to the bomb game. The rules are simple. Use the materials inside this case to kill the other nine people in the enclosed photo. Only then do you get to keep this money." You dig deeper into the case and find a bunch of electronics and a photo that depicts ten people – including you. You don't know the other people in the photo, but you know they're now gunning for you... In Boom, you need to wipe out the other players, while keeping your distance from them so that they don't find out where you are and retaliate! "