One of WiiWare's launch games was Defend Your Castle, a fairly good yet now mostly forgotten title based on the flash game of the same name, in which the objective was quite simple: defend your castle from endless waves of enemies until it finally crumbled. Mindscape and Kaolink must've been inspired by the title, because Army Defender plays almost exactly the same.
Army Defender is played holding the DSi like a book, similar to games like Brain Training/Age. You control a lonely soldier manning a cannon atop his army base on the right (touch) screen, while the enemies will appear from the left side of the other screen. The goal is the same as Defend Your Castle: prevent them from demolishing your base by blowing them all up.
Because of the DSi's touch screen the game is incredibly simple to play. Just touch an area around your cannon and it'll fire in that direction. But that's not all you'll have to do; apparently not one, but two armies want you wiped off the map, and as such both green and red soldiers and vehicles will be attacking you. The solution to this? Simple, just tap your cannon or hit any of the DSi's buttons (Aside from start and select) and your cannon, as well as its shots, will change colour between green and red. You must hit all enemies with the right colour to defeat them — mismatched shots will simply pass through them.
If it takes you too long to defeat an enemy, they'll begin firing at you. Some, like infantry, won't do this until they're right next to your base, but others, such as fighter jets, will begin firing shortly after they appear. Thankfully, shots of both colours will destroy the bullets, missiles and other attacks, but you've got to be quick because they move quite fast. If things get too hairy you also have a special trick up your sleeve — you can tap a nuke button in the top-right corner to fire off a nuke which instantly vaporizes every enemy on both screens. Be wary though, because you've only got a limited supply; you can earn them back by defeating enemies.
It's here where Army Defender goes off in a bit of a different direction than Defend Your Castle. Rather than being able to customize your stats after each round, the game will automatically do so for you. You will randomly receive increases to the amount of shots you fire off per attack, the refill speed of your nukes, and the amount of continues you have. Yes, you read that right — should you fail the mission and lose your base, you've got a limited amount of continues to continue right where you failed, rather than having the last hour or so of gameplay suddenly coming to an end.
The game offers a total of three modes, although they're all practically the same. Tutorial mode will teach you how to play, while Beginner and Expert are both the main game but different difficulties. There are seperate highscore boards for both Beginner and Expert, and that's all there is to it.
The game looks pretty basic, but the graphics have a certain appeal to them. There's quite a bunch of different enemies, and they're all decently well animated. There's only one song during gameplay, and although it fits the army theme well, you will likely barely notice it.
Although there's not really much to do other than playing the game over and over again trying to beat your highscores, it's hard to criticize Army Defender. It does a good job of bringing the popular "defense" game to DSiWare and is fun to play. With its 200 DSi Points price tag it's also extremely cheap, making it one of the better choices in said price range.