I hear you about the progression, as it's not something I added in the game (currently). There is no progression in a particular difficulty but I'm thinking about the best way to add it.
Also, about the blurry shape in full screen mode, it's mostly related to using Sratch and the 480x360 resolution :) It's definitely something I will look into in a future update!
Thank you very much for your detailed and constructive input, I really appreciate!
Btw, great game you did for the jam, it's really impressive!! :)