This was a lot of fun! I'm glad to see that the flower garden tileset was used, and the way you integrated the helicopter into the main design of the second area was cool. I have a few complaints:
You can easily jump over this platform and bypass it entirely.
As much as I like the FG palette, I think the BG palette is a bit ugly and needs work.
Also, you have a few spots like this one throughout this area. It's not entirely obvious that you can stomp down and land safely on a wooden platform. Perhaps you could have a couple of coins indicating this?
Same as the first screenshot, you can easily jump over this platform and bypass hitting the red switch entirely.
I'm not sure why you didn't just finish the last bonus room before putting up an IPS, but either way, I really like this level. Nice work, and I'll give it one last playthrough once you have the final version up.