Played through it. It was very impressive art-wise for 14 days.
The rooms were a bit simplistic gameplay wise (just a couple floating enemies, then next room), but there was only floating enemies and a horizontal knockback mechanic to work with so it's not that surprising.
The 4 main criticisms I have are:
1 - The gun knockback is way way too high. The screen can shake very violently especially during the boss fight where you can fire a lot more often.
2 - You can take damage during room transitions. I think it's taking away my controls whenever I activate those too since that's an especially bad time for the player to be able to take damage.
3 - The crosshair disappears for me on the rooftop with the key
4 - Boss fight's beam attack lingers too long even though I don't think the hitbox does, giving the illusion that it is unavoidable sometimes (especially since your gunshots seem to affect the boss and mess with it's cycle a bit)