Wow, thanks a lot for the very positive review! :D I’m really glad you enjoyed the game.
I think your totally right about the lack of visual variety. We want to have a sort-of world map for the full game and separate the levels by worlds so I think some different colours for each world would be perfect there! We’ll have to see what we can pull off tough since our main artist from the jam got a new job and doesn’t have time to work on the game anymore.