Nice job. Making a mouse only game is certainly an interesting choice. A bit odd, but it also doesn't hurt the experience too much.
The leniency with the jumps in some of the later levels is a bit strict for how awkward the character's shape makes for jumping. Plus I could have sworn that pushing boxes onto the spikes killed me once. You would think you'd be able to stand on top of the blocks to platform easier, but I don't think the game even allowed me to push the blocks onto the spikes before resetting on me.
The music is nice though and the overall theme of the game is a nice take on the theme of the game jam.