Just tried this out! Lots of cool stuff here (dialogue boxes, wall sliding, an upgrade system). The pixel art was nice! I did notice that the 'options' menu seemed to open automatically when starting the game, when maybe it should be hidden at first. like others have said, some of the enemies have a bit too much health, or are a little too similar in their approach (All three bosses could be beaten with the approach of 'shoot in their direction, and jump over if they get too close), but I do appreciate things like the third boss getting a fireball attack that will 'soak' a gunshot, and that there were some changes to the arena for it. Great job!