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.
This is a BG used in Cave Story. It's used as the background for the "Labyrinth Fight" and "Running Hell" areas. It's actually a pretty snazzy BG, and its space on the Map16 is incredibly space-efficient, in case you can't see the screenshot. I would very much enjoy credit being given if you use it, but it's okay if you choose not to.