Awesome submission, albeit a little short, but that's fine for a game jam.
I totally loved the idea of erasing your opponents tracks but in my playthrough it turned out to be almost irrelevant. I never came close to being covered in too much enemy paint and just focused on killing.
So my feedback would be: make the "erase" part a little more relevant to the gameplay!
EDIT: Oh one more thing: You have an explanation in the game start. why not explain the controls there? There are a lot of ppl who don't read the page but rather hit play immediately (so I have learned)