This game was pretty good!
The level design was good, but I think having the camera be a little smaller by default and allowing for panning/zooming would be nice, (the default zoom level is a bit large).
The horizontal requirement to pick up the slimes made it possible to get stuck on some parts, maybe you could offload that choice to an input (like holding space opens the main slime’s mouth to absorb slimes instead of having them repel you), or you could allow for more room on the short platforms in the 4 slime ladder section.
A slime counter would be nice accessibility in addition to the scaling that you already have for the main slime. It’s pretty hard to see how large you are with the zoom as is.
One small weird thing is the double jump item, as it’s a similar to an existing mechanic (slime rocket jump) and isn’t used outside of that one time.
Other than that, the controls were good and well tuned. I had a lot of fun playing through it despite it being short.