I gave it my go finally, I know this is a very polished game at this moment, any comment I make would be ideas to help you "stand out" from the rest of bullet hell type games.
1. There are a lot of bullet hell games with spaceships, if you vary from that, you can fair well, I would suggest add more to the concept of the potato ship, add enemy skins that also are food, when indiegames don't take themselves too seriously, they tend to sell well with the audience. Maybe consider it for an alternative version. Same mechanics, different look, it can appeal to a different audience from the original target.
2. Bullets hell games tend to stand out when the bullets look like "fireworks" visually as in the colors patterns being shot at look pretty on a screenshot, consider that as a possibility to add to your game, right now they work really well as gameplay, but doesn't seem to have the firework qualities yet.
I didn't get very far so I am not sure how many different stages and backgrounds you got, I would say for first few stages, consider making the backgrounds your most pleasant and your best, so you can intrigue players to stick around and want to explore your world even more. I think your story is flexible enough to switch things around.
You are around for the stream but here's the VOD: https://www.twitch.tv/videos/1817769943