I really dig the music in the spawn room and the all-around feel for the content that's been implemented. That ambience does it for me. The art and especially the paint coming off props and weapons is really cool.
I got a little confused when the first ledge you could climb had you sort of slide up, but on closer inspection, it was you clambering up the wall. That's neat and I tried to run up walls to see it in effect. Try to blend the animations in more, so the animations will smoothly go from something like climbing to ledge hanging.
The big issue I found with the ledge stuff was that you could turn around and just float in hanging space. I'm not sure how it happens, but it's when I press back and away from the ledge. I think maybe after inputting forward while on the ledge itself and THEN pressing back? I get the intent is to drop off the ledge- and it works most of the time. But I found myself getting stuck while playing on smaller characters.
The laser cannon seems to aim down on both the LMB and RMB inputs, but only spools up and fires on LMB. If I could make a suggestion, make it so that RMB aims down AND spools up, allowing LMB to just fire. And make a pure LMB input spool up and then fire without any zoom; maybe with drastically reduced accuracy (for a precision attack like a laserbeam).
The shotgun seems to be firing from the camera's position and not the gun or character.