So one of today's XBLA offerings is Defense Grid which I immediately downloading being horribly addicted to tower defense type games. I found myself getting it because it's hard to resist a good game in this genre, especially one like this.
It might not be clear what's going in this image, but trust me, it involves shootin' things.
So, for those few of you out there who may not have played a tower defense game, basically various bad guys walk a path through the screen which you must then defend by setting up gun towers or various types along the route. As the baddies move along, the towers blast them and, hopefully, make sure they don't escape. The trick comes in tower placement, tower type, and how you spend your slow increase of resources to build and/or upgrade your defenses. It's sort of like a real-time strategy game where all the enemies come to you and all you have to do is worry about how best to spend your money on structures without having to worry about all the other clicky stuff.
Defense Grid is similar to most tower defense titles only it has two key differences: 1. There are limited slots where you can place towers, you can't just put them anywhere around the enemy path, and 2. Rather than enemies coming in and trying to get to the exit, most of Defense Grid involves the enemies trying to get to your "cores" (little glowy things) and making off with them back the way they came which means on most of the levels the enemies will be making two trips through the path, leading to all sorts of different strategies compared to most TD type games. The game uses the basic tower types: machine guns, single target lasers, stuff that slows down enemies, continuous group damage guns, etc. It makes no real major revolutions in the tower defense genre, but instead just strives to be a very solid, well-developed addition to the crowd. The graphics are great, the music is nice, and the controls are wonderfully simple and highly functional (I especially like how you can target an enemy and keep it's stats on the screen as long you like, which is VERY useful for keeping an eye on boss monsters). The game's storyline is not exactly in-depth, but it's presented in a clever manner. Basically, as you defend what's left of Earth from the aliens, you're guided by an old computer who used to be a human being. While his voiceovers can be a little annoying, they do admittedly help as he alerts you when certain types of enemies are coming and when cores have been taken, which helps alot during the chaotic moments.
Initially I was skeptical about paying $10 for this game but I am pleased to say that this is definitely worth it. The overall presentation and amount of levels (of which there are MANY more than what you usually get in TD games) easily sells it and the $10 is in fact cheaper than the PC version, which is interesting. I've played tons of these games and this is easily one of the best I've ever played if for nothing else than it's unique approach to slightly altering the tower defense strategy and amount of levels and awards to get. This really should have been part of the whole Summer of Arcade thing, but in a way, maybe it's a good thing it was spaced out some more.
As far as I know, there are no other defense games on the 360 other than Crystal Defenders. There's a South Park themed one coming out soon, but otherwise nothing.