I've played the first level so far, and I'm liking the verticality in those larger rooms, great use of the space ๐ Smart implementation of Custom Modifiers, too.
The weapons generally feel good to use, with suitably punchy sounds, although I think the damage output could be tweaked a little bit - the weapon in slot 1 ought to hit harder, as it only feels slightly more powerful than the starting pistol at the moment.
Great start on the whole! ๐