Twelve hours are almost up, so time for the second hint. Not a hard game to guess;
#12
This game features many unlockable "cheat-codes". My parents made me turn on a specific one every time I played it because it made the nature of the game seem that much more innocent.
Hint 2: Instead of bullets and gore, it became a paintball match with this cheat. At least they didn't make me shake hands...