From my meager experience with shumps and bullet hell shooters, I can say that this is shaping up as a really good game.
You guys could add some border art to cover up the black bars that flanks the gameplay area for people who can't or don't have a display that they can easily turn vertically, maybe move some of the ui over there too, add some high scores to beat with the clear times listed too, along with a run timer.
Additionally, maybe you can add a graze mechanic to incentivize a more aggressive playstyle as demonstrated by the mech suit. Though that begs the question: what is the ship's hitbox? That is one of the parts where I gets me damaged most of the time besides my clear lack of skill.
Finally, how about a demo stage where we can try out the ships for a spin if you won't have some sort of codex for us to read to know what each ship's abilities are, maybe some enemy info would be good too.
Thanks! Border art/gadgets, visible hitbox, ship tutorials/missoons are planned. The run timer seems unnecessary since it's an autoscroller, but a dedicated speedrunning mode/set of missions is something I'd love to add. I think there's enough incentives for aggression as is though since you get more energy, extra enemy spawns and higher damage. Grazing tends to do the opposite and encourage herding bullets while sitting somewhere safe, unless it's Psyvariar style grazing that is.