Thanks for this neat game. Can I suggest a few possible improvements for a future revision?
After destroying enemies suspended from the ceiling, it's sometimes impossible to collect the coin; it would be nice if it dropped.
Bumping the character's head against an overhead platform makes him fall straight down, and some areas require pixel perfect jumps, for instance, when backtracking from the screen that leads to door 2 when the keypad has not been found yet (early on, on the left side of the map) requires jumping over a flame to a high platform; it would be nice if the engine was a bit more forgiving.