So this was my original time when I first finished the game. HOWEVER, this isn't my actual time. This game took me several hours, on top of the 30 minutes that is seen in the screenshot above. I think you might need to add an extra time slot to account for hours.
Another issue that I came across was with the spring boards (or red buttons).
When I jump onto them, for some reason my jump is nullified (like it's a normal jump and not a spring board jump). Regardless of whether I jump or move onto the spring board or jump while on the spring board, I should be able to jump equally. Though, if this is by design, don't worry about it. I learnt to deal with it.
This one for me was massive.
I was stuck on this section for the longest time because I couldn't discern between the fireballs that were shooting downwards and the fireballs that were shooting vertically. It all looked like a jumbled mess. Even though there were only 6. My suggestion is that you make the downwards flames a different colour, like blue. Or, you could make them vertical flames that spray down from top to bottom, instead of shooting out (hopefully this makes sense).
The screenshot above shows the how the time has elapsed passed 1 hour, though it would suggest that I was actually at this level in 44 seconds. Which doesn't really seem feasible right now. (Maybe it might be if people want to truly speedrun it).
Final Area (Test of all your skills)
Dude! That whole section was difficult, and it was made more so by the fact that you had to restart the section from the beginning completely. Man, I understand that it's a hard game, but that was brutal. I think the thing that obliterated me in my first playthrough was with arrow platforms. I prepare to jump onto another platform when out of nowhere, one of those arrow platforms squashed me. I would be completely okay with this, if it wasn't for the fact that I had to restart the whole level again. I can't give you any suggestion because I don't know if you intentionally wanted that to happen. So, I'll just leave this here as me ranting.
This screenshot above is from my second playthrough. There's no way I beat the game in 7 minutes. Because I didn't. It took me 2 hours and 7 minutes to beat it.
Music
I really liked the music. Especially the second area music. The woodwind section was so good. I quite myself whistling to the tune quite a bit.
I think the game is decent. Just those minor things that I said should be taken into consideration. The platforming is very tight, and that's okay. Thanks for making this game dude and keeping making more. You've got this!!!!!!!!!
(P.S. Please add an option to make the game full screen on the browser, it was kind of annoying not having that there.)