What we are offering are legal and genuine Digital Downloads, but sent in the form of an account. After purchase you will receive an account with prepurchased game, put it on your console and use to start the download. Then you will switch back to your own profile and play. The game comes directly from Nintendo eShop, you will be able to go online, get updates etc.
After setup process the game will be available to launch on your own account, just as any other game or app you purchased directly in Nintendo eShop.