It's certainly an interesting submission, the small bounding box with the bosses moving around is a cool concept and reminds me of Undertale. Moving and shooting independent controls, its simple but feels very good once you get used to it
The visuals and sound effects are a bit bare bones but what's there works well enough for the game.
The coolest part for me was how killing one of the hands would not just change phases but alter the attack patterns based on which hand(s) were left. i.e. you have to face the 'consequence' of which hand you chose to kill.
Whilst I get what you were going for with the hp mechanic, it felt a bit too punishing for a single mistake. The orbiting shields are fine and offset the speed loss, but the shield felt bad to use and often I'd lose shortly after dropping to that last hitpoint.