...didn't think level used to have a background? Eh.
As for the gameplay itself, I think it's a creative execution of the fire/ice gimmick. Some parts actually felt too easy
for world 7 - namely, areas in the first half. Other parts felt a little rough around the edges. I'll point out a few below.
I gotta say, I really dislike the use of first-person.
Sort of blind coming back down, especially since there is a pit right to the left of the player. Might be worth setting this part up so that you can actually see the platform below.
Consider adding a second reflecting fireball in there. As it stands, staying to the right renders it pretty harmless.
..come to think of it, as a whole, that is a pretty easy coin to get. Why don't you try moving the fireball block over to the right a bit and throwing some firebars in as obstacles?
Extend the platform below one tile to the right.
You're making me spin jump on a Podoboo?
Get rid of this wall, as it adds a rather iffy effect when you enter the pipe.
Honestly, the throw block generator seems completely arbitrary. Why don't you just put 3-4 regular throw blocks in there?
Whoever coded this block needs to make the fireball spawn a few more pixels to the left. As it stands, it's possible to get smacked by it if you're on the right side of the block.
See the hole above? Move it to the left one tiles. Given the slippery physics, it's very possible that someone could fall, tap right a tiny bit, and die.
Other than that, it's a pretty creative level overall.