Good God.....I am certifiably addicted to this game. I grabbed the demo from that site listed instead of from Steam, and I couldn't put it down for 3 hours straight.
Ok, here's the deal....it's one-on-one battles using a flying machine equipped with various weapons. It's physics based, and you have to get the momentum of your swing to hit your opponent with your weapon and do damage. It's really gladiator-like in the battles, arenas, and even music.
The demo, from what i can tell so far, starts you out in a slow machine with a weak ball-and-chain, while your opponents gradually improve with each battle won with stronger machines and better weapons. Some have swinging hammers, some have swinging swords. You can buy and equip shields, and during battle sometimes items are tossed about that can inflict major damage on either fighter...like a vile of acid that when hit and exploded, sends a stream of acid that does damage to anything it hits.
The levels i've seen so far are varied and interesting, with walls and barriers and such that can do damage if you fly into them, and are even destructable when hit with your weapon.
There are some annoyances that i've found so far, however, like a cheating AI sometimes maybe. And you can cramp up your wrist in short order from the constant mouse swinging.
But this game oozes style and fun. http://www.koshutin.com
and the Steam site http://store.steampowered.com/app/41100