I like the concept of the gameplay. The wild movement and jetpack as a limited action could be used in really fun ways! But I found the very first bits of the level design frustrating, because some jumps were only just barely doable with the jetpack filled all the way. There was also a tutorial explaining how to pick up items, but I never learned what item I picked up, why I did, or if I could use it.
As for the Gameboy part of the jam... the resolution, graphics, and audio don't fit within the limitations of the Gameboy. The limited colors are fine, but the window's not square and the audio uses realistic sounds (the Gameboy could only produce sequenced music on a handful of waveforms and audio had to be intensely downsampled through DPCM). The physics are also likely not possible on the Gameboy. I'm no programmer so I can't 100% verify that, but the amount of smoothing between values required to recreate that feel could take up a lot of processing time.
This'd be a cool gameplay mechanic/vibe for you all to improve on post-jam though, I like the premise a lot :)