Given the feedback from you on my game, I thought this was going to be a longer game and had more thematic elements than "Erase the enemy". That being said, given that your game is about erasing the enemy's pixels I would suggest an Autofire, given how fast you shoot already. Another thing is that the hit boxes for my bullets and the enemies aren't very forgiving meaning most of the game was spent aiming than platforming or exploring the levels.
That being said visually it's a nice game and I love to see more from it. My biggest take away would be to make the game involve more Erasing mechanics rather than just framing "do damage" as "erasure"