The only game I can think of that might qualify as obscure is Jeanne D'Arc. Unless you want to count a few less popular JRPG's like the Dark Clouds and dot hack games as obscure.
I was trying to not say those two, glad to see I wasn't the only one who thought of that :D
Since theres no wikipedia page for it Teen Titans 2 for the GBA,Its a sequel to the original game,I haven't seen much stuff for this online.