You have created some really nice, distinct & personable characters (particularly the very sympathetic lead character) from a very restricted graphic/audio palette. Nice work.
The animation/sound design of the "chomper" is particularly visceral! *shudder* :)
In terms of game play it was quite engaging, particularly initially. I feel like there were places later in the game where "what to do next" could have been a little more obvious--sometimes the guidance was a little *too* minimal. Eventually I found the re-tracing of steps a bit too repetitive for my tastes--particularly when it wasn't always clear if I could pick up the "shiny thing" with my current skills or had to wait until later.
One major bug encountered while playing was that after gaining the "jump/jetpack" skill the character somehow got "stuck under the ground" where it could move but couldn't return to the proper play area. It wasn't obvious at first that this was a bug which made it even more confusing! Had to restart the game to proceed.
Overall, you did really well at communicating with minimal use of text--I particularly like the "next level/power-up" indicator on the rocket ship.
Clearly you put a lot of time & effort into getting the game into a well executed package--and doing the programming, graphics & music yourself makes it even more impressive.
P.S. Nice to see people using LMMS. :)