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 around 100s left on the timer, others might run out of time on their first try.
I should have something witty to put here (even if it's just to update dated info), shouldn't I?
HERE is something that done in ~2-3 hours much earlier today but I don't submit contest entries until closer to the deadline due to a competitive mentality I get during them. This will be very lucky to even crack the top 10, though if it breaks Top 5 I'll be goddamn surprised with myself. Assuming of course, it doesn't get disqualified for some oversight. Since you said only the level will be judged, I will hold you up to that and did nothing with the title screen (it's possible to die, but it takes about seven seconds for that to happen; meaning you have to be slow as molasses) or the overworld.
The base I used for this was my main romhack project, which explains all of the non-choco stuff and the complete lack of a Spin Jump, along with some other mechanics. The more essential stuff is explained in the level itself already.
I should have used more time on this level but I need to go to sleep. This level is probably a bit longer than it should have been. Also, I have finally submitted something to this site that wasn't just a palettes or random screenshots of my levels.