The gameplay is nice and a well-designed twist on the Snake formula, although others have already mentioned it is a bit prone to bugging out :)
I like the choice of music, and the Manifesto, even though it's probably not the best text Marx and Engels put out, is short enough to accompany a game like this. I wonder if there is a way to more organically mix in the text into the game, like having it being read during gameplay perhaps? Just spitballing here, since at the moment, it's of course the usual gamer instinct to just skip over it.
One more criticism though: When I was in level three and hit pause to get up and make a coffee, I accidentally exited to the main menu, because I did *not* expect that to be a quit to menu button and clicked it out of curiosity. :D Maybe making it more apparent or having a safety "are you sure"-dialogue would be a good idea.