I really like the concept of this game and how cute and colourful it is! I like the idea that the further you get the more you upgrade your character to go further. A few notes though:
1) Don't forget to add a way to exit the game (not a problem I can close it externally, but in game would be great)
2) If you continue on with the project make sure that the jumping distance/height is a bit longer
3) Picking up the boxes weren't as straight forward as they should be. I think it would be better to press F to pick up instead of enabling pickup. Just so that there's more direct/instant feedback for picking up the box.
Great job though!
Thanks a lot for the review, those are some great suggestions!
We do not plan on developing this project further, but after the game jam ends we want to change some settings, (Mostly what you wrote) and implament some stuff we planned on being in the game but didn't make it in time. (It nudges us alot :P )