Interesting concept! The lack of visual/audio feedback made it really confusing as to what I was/wasn't doing. I feel like I might have been missing a control or two? The hud had quite a few icons, I was only able to do 3 of them or so.
The icons are hovering (holding up while jumping), gun (shift), speed (you just get slower the lower that one goes), jump (up), grenades (space) and sight, which also just goes down like speed.
But yea, I definitely need to work on the feedback for a post-jam version.