Hi. It's the third game I play in the game jam. And I liked it, but here's my opinion.
(Also I'm sorry if my english is not perfect, I'm french)
Goods:
-The ambience is very cool. The whole artistic direction (especially the music) is giving a cool mood to the game.
-The square (like if they were popping out). And also the level transitions, like if it were all continuous and "it nevers end" ;)
-The level design is pretty good too (even if the levels are too easy).
Things to change (in my opinion obviously):
-There are too few levels, and the fact that they are in random order make it so we can miss some of them. It could have been cool if they were dozens of levels (that's maybe a lot for a game jam I know) so even if we don't do all of them we can still appreciate a big part of them. Because here I didn't feel like I played 11 differents levels (I don't know maybe I did all of them). So pretty rapidly the game feels like it has given all it had.
-Like I said just before the game is fastly finished, you could have added a few new mechanics, maybe like some square where you can go but it stops you and you can go in any other direction after (I don't know if it's really clear sorry ^^ ). Or maybe some pits which you can fall into... Or even a mod where you control two squares at the same time I don't know, the possibilities are infinite.
-And maybe you could add some sounds effects, like the square popping out or when you beat a level.
Generally:
A good and simple game, but I think you could have done more.