I liked the verticality of the map, and it seemed to be absolutely huge!
Though in this case, it might have been a bit detrimental. I wasn't really sure where I was going or what I was trying to achieve (other than just killing people). (It might have been useful to give the player some direction?). So I continued going right and up as far as I could, and eventually (after quite some time) got to what seemed to be a dead end. And the comparatively low amount of variability in the gameplay didn't really suit the size of the map. I got into a routine of just running in a straight line and shooting whenever I saw someone.
I wonder if a smaller map with tougher enemies might have been better suited for this; i.e. making the combat instances more difficult and time-consuming, and making the map smaller to compensate for that. E.g. the skateboard guy could have been an interesting enemy, but he dies with one shot of any gun. I.e. there's no reason to ever have to jump over him to avoid damage.
Anyway, not bad. Cool music as well.