The starting weapon is too loud, it feels more like a bonus superweapon. I don't like how moving forward on ground is slower than in air. Strafing feels pointless (it's slow, meaning skilled play disincentives it, the exact opposite of skill-based mechanics). Managing both bombas and subweapons is too complicated. Subweapons requiring ammo feels unnecessary. Projectile spamming/spawning enemies should have a windup animation, so you don't get hit out of nowhere (e.g., those plants spawned enemies on top of me). Enemy spawners should have a limit, as eventually they fill the screen and become unwinnable. Homing enemies trying to slam into you from your weapon's blindspots (up/down) feels lame, since not being able to aim up/down is artificial, and the game should not bring attention to that.
The basic gamefeel, sounds, and graphics are great, but outside of that it's subpar. The mechanics feel slapdashed and don't blend together.