Whoa, what an incredible game! I love the intensity that this game brings: so many explosions, crazy gunfire, leagues of enemies to blast through, and the bosses, oh man, the bosses are absolute dynamite! When I saw the first boss running with those iconic gunstar-esque limbs, I knew I was in for a good time, and it just kept escalating from there with all sorts of cool variations in level design like battling through a level while being lasered at, or running down a collapsing bridge. Weapon-switching mechanic was pretty neat as well: I thought it felt really gimmicky at first, but I did feel it lead to some cool dynamic fights where you need to be ready to improvise at all times.
It does have some minor issues: for some reason the game's volume is incredibly muted, and even then, I think there is a distinct lack of sound effects in the gameplay, particularly for the enemy death explosions. Sometimes the readability of the game suffers from so much shaking and explosions that you can get hit from a bullet you didn't see. One of the stages just had me stuck at the beginning with no way to proceed until I selected to just skip: bit of an oddity. Finally, the controls can be a bit awkward to get used to, with weird things like having to stop shooting just to pick stuff up, even if you're standing right on top of the pickup when shooting.
Still, this game was such a trip! I'd recommend dressing up the title/intro a bit more as right now it is a bit drab: people need to see a hint at how epic the game can be!
EDIT: AHHH THAT ENDING SEQUENCE AHHH! I never thought a vending machine would make me feel so many emotions