Hmm, this is a pretty neat game! It's pretty blatantly a top-down shooter clone in the vein of games like Binding of Isaac, but for the most part it's got some solid construction to it: enemy/weapon variety is nice, the graphics and story are cute, there are nice quality-of-life features like controller support and a testing area in the hub, and everything just feels very smooth and polished overall. The standout element for it is definitely the boss fights, which were pretty cool with some interesting and challenging patterns. It's pretty impressive!
Since you're going for a commercial release on Steam, though, I feel like I have to be a bit more critical since that's a much bigger arena you're stepping into. And to be honest, I don't think this game has enough going for it to stand out in that crowd, as to me, it just felt rather generic and derivative, all stuff I've seen done before, but better elsewhere. There's nothing wrong with imitating your favorites, heck, we've all gotta start somewhere, but when looking at this, I see no reason to play it over the original deal, nothing that sticks with me or hooks me in or, most importantly, makes me whip out my wallet.
I can offer some slight feedback here and there, such as how I think the feedback for damaging enemies should be more satisfying, possibly by adding blood splatters, and that the weapons are rather boring and could use some more exotic choices, but those are all just minor: the core gameplay loop of simplistic arena combat just doesn't have enough spice to it, apart from the boss battles which I mentioned before. It would be up to you to see if there's something special you can add to this game to make it stand out, something to finish the sentence of 'it's like Binding of Isaac, BUT..."
That's just me, though, and like I said, the game does have a very nice look and feel to it, so you should be proud of what you've accomplished, and best of luck on the release!