Here's something crazy cool for you guys, I found an awesome game with a decently sized booth that you probably haven't heard of. It's called Defenders of Time and it's so cool it doesn't even have a website, that I can find. Anyway, the game was one of the most fun I played at E3 but we have to take into account personal bias, I love tower defense games. They're the best, and this game is essentially the most tower defense game I've ever had the honor of defending with towers.
Basically, it's Tower Defense Survivor from Warcraft III. A sub-section of maps that focused on sending creeps and building defense. Except it's also got a lot of Wintermaul in it, where four players build cooperatively to defend against the siege from four other players. A single commander handles upgrades and creep sending while the three other players work on building the defense. The commander is capable of suggesting locations to build towers.
The fun thing about this game is that it has 100% resell. If you don't know tower defense games then you don't know what this means. This means that you can completely alter the map very rapidly by deleting and replacing towers. Additionally, it has one of the coolest air systems I've ever seen. Essentially flight paths go throughout the map and you can utilize white towers to sort of "pinch" the paths together.
Mazing is a huge component of the game, actually, the main mechanic. The map that I was able to play was intelligently designed to move creeps around in. You start off building mazing towers that do very little damage. You have a short amount of time to start building the key components of your maze before the basic towers become ineffective. Then it becomes a big issue of building the proper towers to fight the proper mobs, a standard tower defense mechanic.
Throughout the game (that I sadly lost), there was a lot of fast paced decision making and high energy trying to map out a maze while fighting against the enemy's constant onslaught. In true TD fashion, the game eventually led to a snowball effect where we were just too ineffective against their sends and collapsed, losing the game.
There are a few tower defense games out there in the market. Kingdom Rush, Creeper World, and Fieldrunners are more of the current popular series. There is about 66 titles on Steam right now, but that includes spillage from games like DotA 2 that have towers in it, which I mean, technically you defend, but eh I don't see it as anything like say Fieldrunners.
Anyway, if you spent your childhood like me playing TD games on WC3, then this is something you're going to want to look at. Gameplay was smooth and felt just like the TD maps you can play today on SC2, if you remember where the game is installed waiting for the next expansion to do something with it.
I wish I could tell you guys more about this game, I really do, but as of right now I'm limited to my experience with the game at E3. I was really impressed out of nowhere with a game that I had no clue existed and will be patiently awaiting more details about it and its launch as time moves forward.