Hey, that's a really nice submission!
Good job on the game it's very well done. The only thing I will mention is the boss, since it's based on time you just have to survive and it can be very long. Could be nice to give the canonballs some effects and maybe reward the player if they hit one of the tentacles by reducing the time a bit? Other than that, the shop system and avoiding the objects seems good!
Congrats on the game ^^