Lego Battles for the Nintendo DS is a good way to spend some time when you can’t play a PC real-time strategy game.
The stylus acts as the mouse and it is very responsive. The AI can be clumsy at times so you’ll have to babysit them as they walk to the right direction. Other than that everything works fine.
I found myself playing more of the Free Play mode as the story in hthe single player mode is kind of a generic RTS plot.