It's a really simple concept and I love the inclusion of multiplayer - it gives the game a really competitive aspect. Against the computer, though, the winning tactic is basically just to avoid the bot and let it kill itself, which isn't particularly fun 😭
I would like to see a lot more content here. I am imagining powerups that spawn randomly in the arena - speed boosts, a "pulse" ability that knocks back the other player, that sort of thing. I think this game really wants to be about controlling the space, and some extra objectives would work well for that I think. It looks fine, I appreciate that you went with red and blue instead of red and green, which makes it readable for people with the most common type of colourblindness :)