Really neat action game, the visual presentation is already nice, only thing maybe would be add destroyed machine particles into the mix for maximum carnage feeling? And some mild screen-shake when the player gets hit for more umpf.
Sound design is also fine overall, maybe add a slight random pitch-shift to the player shoot-sound so it is not the same sound constantly.
The main problem i have is the longevity of fun. The first 3 levels were neat figuring out controls etc and trying out a few powerups, but after that every level felt similar. The best strategy is to circle the enemies and keep shooting. Yeah i can try to aim for core turrets to kill the whole thing faster, but the added risk is mostly not worth the gain.
I am not sure myself how to change that. Maybe change the base shooting patterns to allow dodging on the spot and skillfully aim for core turret?
Also maybe instead of a power-up system have a permanent upgrade-shop that player buy stuff either for each run or inbetween levels. That would give me more of a progression feeling.
Or go the full rougelike route with procedural levels and randomized bonuses after each level and really crazy shooting synergies XD
Ohh and i was able to use my controller for movement, but nothing else in the game. Either disable the controller completely or add full controller support, was a bit confusing for the first few seconds ^^