It’s the classic Missile Command game, rewritten for the Nintendo DS! Shoot down the incoming missiles and protect your cities. Earn a new city every 10,000 points or, if you already have all four, get a huge point bonus.
High scores are automatic if you have DLDI patching. Most modern cards do this automatically, but if you don’t see high scores showing up, you need to manually DLDI patch. The scores are stored in the DATA directory, if one exists. Otherwise they’re stored in the root directory.