Headline Feeds
"Star Defense," a game by Ngmoco, is available for US$5.99 at the App Store.
Just about every "tower defense"-style game ever made can be described like this:
You've got a base you need to protect. Wave after wave of bad guys keep on attacking it, running down a long and winding path before, I don't know, running face-first into the front door, or something. Point is, when they reach the gate, they do damage, and it's your job to strategically set up a bunch of defensive towers along that path and shoot, bomb, pummel and blaze them before they get to your doorstep. If your gauntlet fails to take down a certain number of attackers, you lose.
This set-up leaves a lot of room for variation, and developers have played around with it on different platforms for years. The iPhone has several tower defense games available for it, the latest being "Star Defense."
Barbarians at the Gate
"Star Defense" doesn't waste much time with story or plot. After choosing a difficulty level, you're presented with a base to defend and $50 in the bank. The money is used to build new defensive towers to guard against waves of increasingly strong monsters. You get a few bucks more each time you destroy an enemy ("S'rath," they're called -- not much back story there either, except that they seem intent on attacking your base of space colonists).
There's some variety in the towers and what they're capable of. Some are designed for pure destruction; others are built to slow enemies down while the other towers do their worst. Position your guys accordingly. Once you've built towers in the most strategically important bottlenecks along the path, you can buy upgrades that improve power and range. As you progress in the game, more types of towers become available.
The S'rath themselves are varied as well in terms of appearances, strengths and weaknesses. You'll have to build a diverse portfolio of towers in order to succeed.
Planetary Battle
This probably sounds like just about every other tower defense game ever built. However, the unique thing "Star Defense" brings to the table is that the maps are three-dimensional. Each series of battles takes place on a little planetoid (most are spheres, but at least one's a cube), and you have to use the touchscreen to zoom in, out and around as you manage your defenses. It takes some getting used to, but it's more interesting than your typical flat map.
"Star Defense's" music and graphics are well-polished. These types of games don't really require much in the way of artistry in order to show you what's going on, but some added detail like what you see here makes it even more fun to watch stuff get blowed up good.
Bottom Line
To me, a decent tower defense game is every bit as addictive as "Tetris," but with the added benefit of explosions and destruction. If you're familiar with the style, "Star Defense" is the one to have on your iPhone.
If you're not so familiar with the style but think you might be interested, try "TapDefense" first. It's a free iPhone/iPod touch game that isn't quite as well-crafted as "Star Defense," but it'll give you a good idea of what this sort of game is all about. If you have any sort of fun at all with it, the $6 upgrade to "Star Defense" will be worth it.
Talkback: 
