The song is so cute! Fits nicely with the aesthetics. Damn I really love your GMTK entries lol.
The small dust clouds when the characters lands feel a bit odd, due to being so static.
On the 4th level (I guess, the one where you scale a box appearing on a portal up), I think I died while spawning carrying the box, dunno why.
Sometimes carrying a big box through the portal bugged the box, like it clipped out of the stage.
By the way I couldn't get past this stage, either I'd get softlocked or would die not able to spawn again when carrying the box through the left portal.
Kudos on making such a charming fun puzzle!