There's a solid foundation here, I love pretty much any aim to shoot game people throw at me, but making it all the way to the third area it felt very repetitive and like the game didn't have much to throw at me. A majority of the rooms are wide open spaces with the same few enemies, most of which can easily be knocked back with the basic, quick firing pistol before they have the chance to melee you, and even the enemies with projectiles are usually too busy being knocked back to get a hit in. I only really started having any trouble in the third area with the invincible cannons.
If I could suggest anything, I'd probably remove the player's ability to destroy enemy bullets. It just makes the first two areas far, far too easy. I'd also try adding more platforming, and rooms designed around the enemies in them, and less horde rooms with multiple wave spawns that all feel the same after a while. Maybe nerf the starting pistol too, it's just too good against melee enemies, they don't have a chance.
On the positive side I love that you can roll in the air, that's cool and provides a really funny movement option. This kind of run and gun gameplay always gets me going, and movement options like that make it all the better. Wish you the best!