Thank you very much for you feedback! You're not the first way to say that guns feel weak or that the enemies are too strong, especially the spiked flies.
By the way, there is a way to move vertically using guns! By aiming down and shooting, your gun acts like a jetpack. Maybe I didn't communicate this feature well enough, please tell me if you didn't know about it!
And I really like your idea of blast, which could act as a sort of dual-purpose reloading system.
I'll work on an update to improve these points, and thank you for playing! :)