The NES-aesthetics are amazing! Took me a while to figure out to pogo, and these bubble jumps are really hard to pull off sometimes :)
I like the level progression, where you learn the mechanics first, and then you need to master them to succeed later.
Compliments on the graphics once more - everything from the flashy title screen to the animations in game... great work!
Edit: I'm not sure if it's intentional, but the background music seems to be stereo, and "moves" between the ears, as you move around the map.