The DS Lite is definitely one of the better handhelds, and by far my second favorite (only after the 3DS now). The only problem I ever had with mine was that the right hinge tends to break after a long period of time (sadly, that's happened to me twice, with two systems I got the previous two Christmases to replace my original one).
I never played any Megaman Starforce games, though, so I can't offer up any advice.