The "tower" enemies seems to be a bit of chore to fight against - you can defeat one before it starts shooting, but if there is a lot going on around then you end up hiding behind that bus and waiting them out while you defeat the mooks and if you screw up a block or dodge then you get more blasts for good measure.

Maybe make their "charge" shorter, but with single shots? That could make a constant, but not overwhelming pressure upon player. Maybe add the possibility to interrupt it by attacking it.

Besides that, it's a fun game.