Chex Quest for PSP is a non-violent WAD mod game for the DOOM engine.

Controls:
Analog UP = FORWARD.
Analog DOWN = BACK.
Analog LEFT = Look LEFT.
Analog RIGHT = Look RIGHT.
START = ENTER.
SELECT = ESC.
CROSS = USE.
Dpad UP = NEXT.
Dpad DOWN = PREV.
Dpad LEFT = NONE.
Dpad RIGHT = NONE.
TRIANGLE = MAP.
SQUARE = Strafe LEFT.
CIRCLE = Strafe RIGHT.
Left TRIG = RUN.
Right TRIG = FIRE.

Known Problems:
Once you load the game on the PSP if you don't choose a level and setting quick enough it will freeze and you will have to hit home to quit. (So I suggest just load the level quick then go to the menu and select your settings and load a new game).