Great game, it's a neat concept and the difficulty was well balanced (struggled a bit with the last two levels but they were never frustrating, just tricky). Would be curious to see how you'd expand on the level design and any new mechanics!
My one note would be that the geometric aesthetic of the art doesn't seem super cohesive with the story of a guy trapped in a cursed banjo dimension. Seems like it should a more mystical vibe (maybe something along the lines of the old Doctor Strange comics, or the magical bits of The Princess and the Frog Disney movie, but you could go in a lot of directions with it, so whatever you like). It would help a lot with the immersion.
Had a lot fun tho, great work!