I think there is something wrong with the build you uploaded, I can't really do much beside jumping around a really really small square. Good job nonetheless!
Viewing post in Achievement jam comments
Thank you for your comment! Sorry if it wasn't clear enough, we don't know why Unity made changes in the scene after building the project, but you could navigate to other levels if you go to the edges of the scene and then click "E" standing over any edge :] (It was also supposed you could also choose your skin in the middle platform, but we couldn't achieve it correctly).
Top right edge - level 4, Top left edge - level 5, Bottom right edge - level 2, Bottom left edge - level 3