I really like what you've got so far. I feel the overall speed of things could be increased a bit to help nail that Quakelike feel.
It seems like any small bump in the ground will cancel out the dashes momentum, which happens often when just running on foot.
Slow mo doesn't seem to last long enough to actually gain use out of it.
I absolutely love the artstyle you've got going on. I've been learning Unity for a couple months, and would love to know how you got the almost exact quake like feel to this with the pixely wall textures without smoothing.
An option to have weapons be centred like older shooters would be nice as well, but I realize that's a niche kinda thing.