My first review was that this was a chill game and that I wish i could upgrade the weapons.
AND THEN I FOUND OUT YOU COULD! I think there should be a better visual indicator about upgrading the different weapons.... at least that would have helped me.
I think there is also an opportunity to add background cues to your movement direction. With the way the camera works, without many enemies on the screen, it can be hard to know if you actually switched directions.
Very fun, pretty well balanced. The effects all come together. Very well done!