Tip: When determining a time limit, remember that players won't be as familiar with the level as you are. If you normally complete the level with the timer around 100, others might run out of time on their first try.
Updated to fix a potential crash when the keyhole effect is activated at certain harmless-looking screen positions. The effect now appears at a configurable hard-coded location, the middle of the screen by default.
Tested with Asar 1.71, Lunar Magic 3.04, SA-1 1.32, Snes9x 1.59.2, GPS 1.4.1.