Bioshock + Half Life + DOOM 3 = Prey
You got all the good game material into one game, very good story, game mechanic.
=> Problem solving by interacting with object in the enviroment from Half Life.
=> Looking for clue like keycard, keycode from e-mail, audio log or tiny notepad on wall that you pick up, or even notice handwrite on wall sometime can give you clue to open door, safe... DOOM 3
=> RPG material like unlocking skill to progress further, repairing sentry gun to help you fight back the creature, stealth and go loud you got what you need, and the swinging hand gesture with wrench very familiar from good old game franchise Bioshock.

The game give you multiple way to solve a problem, for example to open the door, you can tranform into small thing and squeeze to tiny broken window, ventilator or you can break window then use something to hit the button inside the room.

Bioshock + Half Life + DOOM 3 = Prey You got all the good game material into one game, very good story, game mechanic. => Problem solving by interacting with object in the enviroment from Half Life. => Looking for clue like keycard, keycode from e-mail, audio log or tiny notepad on wall that you pick up, or even notice handwrite on wall sometime can give you clue to open door, safe... DOOM 3 => RPG material like unlocking skill to progress further, repairing sentry gun to help you fight back the creature, stealth and go loud you got what you need, and the swinging hand gesture with wrench very familiar from good old game franchise Bioshock. The game give you multiple way to solve a problem, for example to open the door, you can tranform into small thing and squeeze to tiny broken window, ventilator or you can break window then use something to hit the button inside the room.