Take a turn-based war game, add some color and put it on the GBA instead of the PC, does it work? Hell yeah!
Advance Wars is one of the best games on the GBA. The game isn't impresive graphically, like you'd expect at first. Everything looks simple, but behind the simple looks there's a very deep game. With the help of a easy to understand menu you can create new units, capture bases or put an infantry into a ship/APC.
The units are als overy well-balanced, the infantry is very weak, but can capture bases and the enemies HQ. The Bomber is easily the strongest unit, but can be destroyed with an Anti-Air. So just focusing on one type of unit won't get you far in the game (well, not in the later missions). The Campaign can get really hard sometimes, since your opponent ussually starts with more units, buildings and money. And if that isn't hard enough you can still try the Advanced Campaign after that, wich is insanely hard.
The sound of the game is close to perfect, each character has his own theme, and all those themes fit the characters.
If you didn't get the game yet, get it now, or get Advance Wars 2 instead!