Keep it on the down-low, alright, but I think these single-screen multiplayer games could be quite popular. Just a hunch, there's no direct evidence of it being a vastly enjoyable genre, criminally neglected in recent times and with digi-acres of room to grow. I wouldn't want to make any blanket statements, but I think some sort of grenade-lobbing, scissor-throwing, gravity-warping arena would be an acceptable next step. Oh, what a coincidence! I've basically described Paperbound, which combines all that with a gorgeous hand-painted style and somewhat horrifyingly violent stick-figure men wielding swords. There's a trailer and thoughts below.
The first project of Dissident Logic, headed by ex-Transformers and 7DFPS oddity Reflections dev Dan Holbert, I managed to play a build at Rezzed. Vastly improved from the prototype version I'd seen previously, it's a gorgeous and fast-paced game, even with just two players. Movement is smooth, not requiring any particular acclimatisation to progressing quickly from wall to floor to ceiling. Having both a jump and reverse gravity button can be confusing at first, but each allows for differing tactics when approaching an opponent.
The selection of weapons, too, provides a number of avenues for assault. The sword is the most reliable, immediately killing anyone up close, but requires careful timing when two characters are hurtling towards each other. The grenade is more dangerous, but the easiest to use, creating a sizable explosion upon impact with a surface and a sure-fire way to get your friends angry at you if they were mid-duel. Scissors are something of a half-way house, precisely aimed but long-range projectiles that require a little more finesse to use but take less time to recharge.
It's still in early stages, but the foundations of another excellent party game are there. Planned for later this year, experimentation with maps and modes is still ongoing, from competitive one-on-0ne in tiny areas to a football-like version. There's more screenshots and details over on the official site and Facebook page.
UPDATE: Dan e-mailed me about a new trailer they've put together.
He also passes on word that the game plans to hit Greenlight on the 10th of April.