Creative idea, I felt like the second level was too punishing, 3 and 4 where very well designed with the chaining jumps. I think adding some tiny walls where you need to land after dashing could help as most of my failures at level 2 where by dashing too far away. Maybe making the collectibles area a bit bigger or adding a magnet like effect to the player could also avoid the issue of getting a little too far/ too close of them and not picking them up. Overall I liked it,especially because of the last 2 levels, the effect when gravity gets to max is interesting aswell, very solid for a first entry.
An external tip I would give you about 3d modelling is trying out BlockBench (if you prefer low-poly models), its way easier than blender and the results are pretty good, you can fully skip UV unwrapping and paint the model directly which is very usefull, specially if your solo. I have first heard about it from this video