Good work, I am a sucker for bullet hell type games so this was a cool one to play. I found the thing most limiting to my enjoyment of this game was the movement. I played it for a pretty extended period of time and was wondering if experience would help me better control the mech, but it did not. I think if you make the steering a bit more 'snappy' and responsive rather than having some latency when turning would make the game much more user-friendly. Also, the auto-bounce on walls sometimes let to frustrating situations when I would get trapped in a corridor (I believe in the room before the boss there are some tight pathways on the perimeter). My intuition expected the ability to reverse, maybe that's an option open for your consideration?
I really enjoyed the mechanic of dragging and dropping weapons onto your mech. It's passively increases your time to die while also giving you an edge against some of the tougher enemies, so that was really well done. All in all, good job!