Frogger 3D Cheats for 3DS
When you have beaten the game World 7 will become unlocked. Beating World 7 will unlock 8 and consecutively up to World 12. Levels 7-12 are ALL harder versions of worlds 1 through 6.
This bonus feature which is faster and more difficult will become available for the 'Forever Crossing' mini-game when you beat World 12.
The question marks at the 'Main' menu will turn into the 'Challenge' option when you complete the game without skipping over any levels when the storyline branches and ALL the levels are complete.