Compatibility list by dshack.free.fr :
Cool 104 Joker & Setline (J)(Wario).nds
Feel The Magic XYXX (U).nds
Naruto RPG 2 - Chidori vs Rasengan (J).nds (Does not work with Demo Metroid)
Ridge Racer DS (U).nds (Does not work with Demo Metroid)
These roms all load with metroid demo but some of them do not save such as ridge racer, so it is not playable.