For the grandfather of all turn-based strategy games (well, besides RISK), this game is pretty badass. Granted the graphics
seem archaic at first, but the game actually has some good animations where you wouldn't expect it. When the units capture a building, you're treated to a movie of a soldier going into the town and raising his flag (either halfway, or of him saluting you as the flag goes the rest of the way up). Or, when you tell a unit to get into a transport, you see him jump into it.
The AI is also pretty challenging. If I crank this thing up to AI 200, I'll get my ass kicked faster than a Nazi at a WWII veterans convention. The battles also look pretty damn good for an NES. They kind of remind me of Final Fantasy, if your Black Mage got a gigantic tank of death.
All in all, this game's fun. If you have an NES emulator, check the ROM out. If you have an actual NES, contact a Japanese antique dealer and scream "I can't understand you!" into a phone for an hour. He should get the picture.
If you're not willing to get a ROM because the Government has you whipped, and you don't want to contact a Japanese guy for fear of samurai retaliation, you can pick up a copy of Advance Wars Dual Strike. Or, Famicom Wars DS as it's called in Japan.