While many games indeed contain sword-wielding characters, very few make even a cursory attempt actually to simulate the dynamics of sword-fighting, nor yet to impart a sense of how it actually feels to engage in swordplay.
That's what Determinance does. True, what it simulates is less the reality of fencing that the sort of over-the-top dramatic swordplay you'd expect in Highlander or a Hong Kong action flick, but hey, that's fun. What it does, and elegantly, is allow you to control sword motions, body positions, and arm positions with nothing but the mouse and its buttons.
In short, from a UI perspective, at least, this is a highly innovative game. It's also one that takes a while to master; in keeping with other "player-skill" games, you need to train with the interface before you get good. But it does impart far more of a sense of actual sword combat than you'd get out of a button-mashing "fighter" or a turn-based RPG combat system.
As with, say, Quake, Determinance is designed primarily for multiplayer duels on line; while there's a soloplay option, it's against AI bots simulating human opponents, so that the soloplay game is primarily training for online play.
Tres cool. En garde!