Early game is too difficult with the lack of intelligent spawning. Any type of spawner - most notably the squares, who spawn on death - is close to impossible to deal with, considering how quickly you get swarmed even when you have spread shot and fire rate upgraded. You have a bunch of area clear, but you still don't have enough to be able to actually clear out all of the things being spawned. Also, Squares in particular - or other on-deaths, since I'm not even gonna bother continuing - should not spawn a new, full square to replace the one you just killed if the bits aren't dead yet.