Tower defense isn't just for flash games to pick away at when the boss isn't looking. This new genre is exploding all over the videogame scene, leaving plenty of room for developers to come in and refine the formula in their own style. Defense Grid was released a short while back on the PC, where it was loved by people who love downloadable genius, especially those popping up on Steam. Now it's reawakened better and cheaper on XBLA.
The story is understated, but charmingly told through an old British gentleman whose colony had the misfortune of being wiped out by an alien invasion. He survived by being downloaded into computer, and so is there to advise your efforts to drive back this alien menace, with an occasional longing for raspberries.
Defense Grid is a game for a thinking man without too much time on his hands.
The gameplay seems just as understated at first. Each map has a power station full of cores aliens are eager to make off with, a path on which they'll invade, and marked spots where you can place towers to blast them all to smithereens. Things gradually grow more complicated as different alien types appear, and you gain access to different towers to drive them off. A gun tower is a cheap and easy way to expel individual enemies, but it doesn't work well on a pack of the buggers. That's where you're going to need an inferno, or latter on a concussion tower. Many towers to choose from by the end, each with three levels of power to marshal your defense. My favorite wasn't the meteor that dropped flaming rocks from the sky, or the missile tower that obliterated flying enemies. My favorite, the temporal tower, didn't damage them at all. It simply slows down these invaders to a crawl to let the other towers blast them to bits.
Blasting them is the basic way you afford more towers, though you also gain interest on the resources you have left in the bank, meaning more money if you hold off on placing towers until you really need to. You can sell off towers that aren't doing the trick, but as with upgrading, it takes a little time for the old tower to vanish and the new one to appear, and that's time they can't be tearing into aliens. Some levels allow you to place towers directly in the path of your enemies, letting you form mazes of death that delay their trip to your precious cores. Though I wasn't overjoyed when aerial aliens entered the fray, since they follow their own paths, and distract your guns from the guys on the ground.
Controls make it a breeze to place, upgrade, and sell off towers. Same with checking the health and stats of current enemies, with a scrolling preview of the types of foes you're about to face. If you've already got a perfect setup, you can speed things up with the fast forward button, and then hit the back button to instantly revert back to your last checkpoint when you realize it was far from ideal. This keeps the challenge high, while reducing the player's frustration to virtually nil. Getting good will earn you a gold medal and a high spot on the online leaderboards, as well as unlocking several variations of the last mission. There's a lot of content here for a ten spot, sure to last at least ten solid hours.
There are a few small annoyances though. Levels are unlocked in a strictly linear fashion until pretty near to the end, so if you're stuck or just don't feel like playing the current mission, you can't just skip ahead and come back to it later. While the design of these futuristic landscapes is detailed and excellent, the towers themselves can look a bit too similar, sometimes making it hard to remember which one you need to upgrade before the next wave hits. Too many waves and towers filling the screen can sometimes cause the framerate to chug, but this is really only an issue on the last and longest missions. A map editor would have been nice, but a little too much to expect at this price.
Defense Grid is a game for a thinking man without too much time on his hands. Each mission is relatively short and sprinkled with checkpoints, which can be saved and returned to later. Undoing your mistakes is quick and effortless, while maps that seem impossible at first glance prove a delight if you only take them one tower at a time.