Ludum Dare attempt from August 2011, for the theme "Escape", left as is since that time (to-do list and all)
Designed as a game where you attempted to escape from some sort of facility and beat as many AI characters as possible to improve your score.
Primary reason that I failed to finish was collision detection, which proved to be very finicky to implement, being my first attempt at doing so. May, in the future, attempt to make the game playable