I haven't tested the multiplayer part, but I liked the singleplayer so far! The reduced level design reminded me of Antichamber (which I loved) but with less insane puzzles and more vandart. The background track did a good job suppporting the "Run around and do what you like in a futuristic landscape" atmosphere of the game. I also liked that you could run along walls when you jumped at them from the side and kept going, similar to the wall ride mechanic in the THPS series. Not really sure if that was intentional, but I had fun with it when I discovered it and that's what matters!
Different spray patterns would be cool. I also noticed that some colors look a bit different on the canvas/walls compared to when they're sprayed, but that's a minor issue.
Fun little game!