To 100% Complete the Game, you need to:
-Get All 2700 Opals
-Collect Every Golden Cog
-Collect Every Rainbow Scale
-Collect Every Thunder Egg
-Save Every Bilbie
-Get All Talismans by defeating every main boss (Defeating Neddy doesn't give you a Talisman, but a Thunderegg instead)
Picture Frames aren't required for basic 100% but they're still required for a achievement