As anticipated, Nidhogg is a great game. Some of the best sword play I've ever experienced outside of maybe Chivalry.
Here's a video:
So yeah. I personally think this game is awesome, and I think it deserves all the attention it's getting. Also, there is a competitive scene that seems pretty strong. The game is technically very deep, and the fighting game community seems to be rallying behind it as a contender for a showcase game for e-sports.
Sorry about the "e-sports"...