This was a cool entry, the aesthetics were very retro and I liked the variation in all the different weapon types.
I may just be a stranger to this style of to down shooter though because it felt odd to me having my projectiles go to where I'm pointing rather than just the direction my cursor is facing. In the same vein, it was annoying when I couldn't switch to a previous weapon after picking up a new one. Some of them like the vulcan or flak just didn't feel good to me and I consciously avoided them.
On every other front though, I enjoyed playing this!
The music was nice and energetic, the sound effects were good, the artstyle I loved, the environments I thought were good, and I really liked the minimap. It all came together to feel like a nice Mech PS1 experience!
Excellent work!