Asking how new the coin concept is: basically ridiculous. Collecting a certain number of something in order to progress is just as basic a level format as getting to an exit without collecting things. It especially bears little resemblance to FSP (Rent Collection) because the coins are numerous rather than five or ten hidden in obscure places and they're not even all required (fifty necessary, and then apparently another fifty scattered around somewhere else?). Yes, they're all coins, but that's simply what mechanism JJ2 most easily provides for such purposes. It's a gamemode that dates back to Pacman and it doesn't make any sense to point at this or that pack as being ripped off any more than it does accusing Shellion's Xtreme Revenge of ripping off Another Story because both of them require you to reach level exits.