Alright, cool. Was able to find everything. Few more things:
1. Really like the use of the melon bugs in this level.
2. Yoshi enters this screen 1 block too far to the right.
3. Might be worth adding some way to get out of this room more quickly in case the player enters it a second time by accident.
4. Make the entrance leading to this area a bit more clear, like with an arrow sign or something.