Random idea I thought of when I was playing Mario 3 for fun. It's very gimmicky though, so bare with me.
Basically, you're in an ice world and the angry Sun from Mario 3 comes. Now you're in a rush, because the longer you take, the more the place melts (kind of like a really slow moving layer 2 going down or something.) To make it a little more realistic-looking, rather than just a falling layer 2, the terrain can change realistically (e.g. if the snow is flat, it can melt the corners more so than the middle)
If you take too long, you're transported to a timed water level (gotta get out before hypothermia kicks in, don'tcha?) Collecting fire-flowers add time instead of throwing fireballs.
After that, well...we'll leave that to whoever brings this thought into fruition (if anyone does). And sorry if someone posted a very similar idea to this one; I haven't really been able to read the entire thread. =-C
holy dear mother of christ this thing has been released