Well, I think it just comes down to presentation and what I've heard many game devs call "juice". The way the game is now, everything is perfectly functional, but I'm not sure it gets at the themes of what the game is about. Nor does it embellish the feelings you get while you play.
For instance: "Vengeance" is such a serious word for a sort of abstract shooter/puzzle game. But if you're going to go that route, I want to feel like I'm enacting revenge or somehow outsmarting my opponent, which is, I guess, myself. For me, that could mean more vicious color schemes, maybe more "intense" music, more satisfying or gruesome death animations, more interesting player avatars, etc. When I look at the sort of logo image on your game page, or when I read the description, it doesn't really say much about what this game will be like. I would've had no idea it was as much fun, or as challenging, as it actually is. If I can be perfectly honest, I'm not sure I would have played it if hadn't been a part of this game jam. I hope that's helpful, and I hope to see more happen with your game!