The game I played is called Song of Drums and Shakos. This is a skirmish miniatures game set during the Napoleonic era. The rules are based on the game Song of Blades and Heroes, and both are published by Ganesha Games. These rule sets are awesome for two reasons: 1) they are cheap at $8 for the PDF and 2) they allow the use of any miniatures you want. Song of Blades and Heroes is a fantasy based game and works well with pretty much any fantasy figures you might have from Games Workshop, Reaper, WoTC you name it. Song of Drums works equally as well with Napoleonic miniatures from a variety of manufacturers. Both games work well in 15mm and 25mm scales.
As I played I was reminded of everything I liked about this game system. The games actually play quite fast compared to something like Warhammer or 40K. The rules are easy enough to teach to someone in a 5 minute overview and new players are comfortable with the game after one or two rounds of playing. There is enough depth to the rules to allow good tactics to impact the outcome, and enough luck of the dice to make sure that the game cannot be gamed. Best of all this game is about combat, and it is bloody. Once combat starts it can be over very fast. The games is deadly, and that's how it should be.
One thing I will say for OwlCon this year is that all of the people I gamed with were awesome. In years past I have always seemed to find at least one player who wanted to argue rules or otherwise generally be unpleasant. Not so this year. The wide variety of gamers is what makes a convention like OwlCon great, and this year I got to game with the cream of the crop.
If you want to read more about the game at OwlCon check out the write up on the Tactical Miniatures Gaming blog. There are some additional pictures of the game in my OwlCon album on Picasa.