This game was a blast and it's clear that you put a lot of work into it!
I really enjoyed the fast-paced arcade feel that the game had.
Personally, I found it a little bit frustrating that the player was not able to jump through the leaf platforms. Since the character has so much upwards velocity it feels kinda diminishing when you are constantly bonking your head on platforms. This was especially jarring when I saw that the treetops did not have any collision.
Another small addition that I would have liked to see would be some kind of arrow or hint pointing you towards the direction of the final few items (maybe only when you have about 5 or less to collect). I could see how it might become a little tedious to run all around the map hunting for the final collectable if you happened to miss it.
Other than those small critiques I think that this was an absolutely fantastic submission. Great job!