Having so many characters with different abilities is cool. My pick was the engineer, I felt I could speed through the bosses with a fully charged meter and some clutch grazing.
The different characters and boss health bars make me wonder what a speedrun might look like. Which characters can take out which bosses faster?
The player's health bar is fairly generous, and I imagine this would be much harder with only a few lives of single hits. But I think it's well considered as grazing to gain meter is so important. The enemy design seems to be built around giving lots of grazing opportunities.
Great pixel art and interesting character and boss designs are really appealing. I like the little visual flourishes like the tail on the ship and the way the score lights up when grazing. Really well done!