I'm so happy that you've put this out there!
Aesthetically the game is so gorgeous! the flat shading, pastel colours and roundness of everything is just so pleasant! The only thing I felt was a bit out of place was the effect on the vents but otherwise super consistent!
The little guy controls really well and I always felt sure where I was when jumping, although I didn't realise I could double jump initially since it wasn't tutorialised.
I feel like the level design errs a bit on the side of every leap needing the double jump but it was still really good, if a bit simple (but I understand that might be the goal). The mechanics are really well contextualised with the environments!
My only other gripes were I felt like the camera kept moving to a view which was too much top-down that I couldn't see what was ahead and the trees block the character when running around - maybe have a silhouette of the character show when behind an object like a lot of other 3D platformers.
Interested where the cutscenes will go...
Was so fun I played through it twice!