I played this game on Twitch: https://www.twitch.tv/videos/1933487767?t=00h02m10s
I focused on the Hel's Fighters mode, since I played the campaign in the past. Overall, I had a ton of fun! I liked the story in that mode, and the gladiator kind of setting for it.
The beginning was a little rough, where I thought I had to destroy the turrets, when actually I was supposed to fly past them to the doors. Maybe some sort of note/message in the beginning to avoid the turrets might be good?
I upgraded the ship at the shop (the free upgrade), which made a huge difference. However, I did get stuck for a bit right after the purchase, trying to change my ship. Ultimately I realized I had to go back to a dock to do it, but some sort of UI (or message from the shop owner about it) would be good I think!
Those were my main suggestions for improvements, the game itself was tons of fun, even though I died a lot to the spirally things :) Keep it up!