Listing of games incompatible with 3DS save backup functionality

Nintendo pushed out a new 3DS firmware update a couple of days ago that allows users to backup save data. But not all titles are compatible with the functionality.

The games below do not allow for save backups:

Pokemon Mystery Dungeon
Cubic Ninja
Monster Hunter 3G
Reel Fishing 3D Paradise
Pokemon Rumble Blast
Freakyforms Deluxe
Pokemon Dream Radar
Senran Kagura Burst: Guren no Shoujotachi
Sengoku Musou Chronicle 2nd

Nintendo’s GBA Ambassador games cannot be backed up as well.

Source