The concept seemed interesting, and definitely has some potential.  Though the actual movement and mechanics aren't the most polished unfortunately.  One big thing was the difficulty in gathering ammo.  Though I can explain that better in some clearer feedback below:

• The movement felt a bit imprecise and the speeds felt a bit too far in either direction for each gun.  The one you're speeding around the arena at hyper speed.  When with the other you're essentially limping around with a machine gun.  It's hard to specifically pin down what felt imprecise, though it may just be down to the speed, I'm not sure.  
• Picking up ammo was quite difficult due to how incredibly small the pickups themselves were.  Plus for a bit due to how small they were and the seeming absence (which I later found) of an ammo counter I didn't realize they were there.  So I'd definitely recommend increasing the size of the ammo pickups.
• To add onto my last point, the ammo counter was a little hard to find.  Since it was in the top right and there doesn't seem to be too much of an indication of it going up when you do seem to pick up ammo.  Which made it a little hard to gauge how much I had left.  I feel like at least placing the UI better could be helpful.  Though changing it up would be nice as well.

Nice that you can aim with the right mouse click, i played some fps games from the jam that did not have that :P The enemies seem a bit static but overall good job :)

Interesting visual style. In general, it seemed way too sensitive to mouse movement. It was also hard to tell if the enemies were hit or not or if you were hit. Love the general idea.