A devroom button right there that you can't click? That's just mean...
You have a decent chunk of game here already, I feel like most of the things I'd have to say about it would amount to you replying that you're working on it. Basically it needs more stuff, juice and other roguelite goodies. And more visual variation to the levels.
Would be nice if you auto reload when trying to fire an empty gun. Also if there was some indicator to what ammo type your equipped gun is using.
I couldn't reload the particle accelerator even though I'm pretty sure I had the ammo for it:
I entered a level ontop of a boss once.
Exits are a bit awkward, I accidentally stepped on one while fighting a boss once. Guessing the exits won't be available all the time later. Would be great if there's some sort of indicator or arrow or something to guide you to an exit when you've killed all enemies.
Keep up the good work!