While the carts do have only a few different games, most of the entries start the game with different memory hacks, most noticeable on Super Mario Bros.: it's possible to warp to any world possible (including the glitched ones, starting from 9-1) or enable the "moon gravity" mode. Also, Galaxian and Lunar Pool, depending on the selected menu activity, warped the player to a different level (in case of Lunar Pool, with the internal stage selection disabled). The many modifications of Tank 1990 were split into different entires on every such multicart, while Duck Hunt and Wild Gunman usually had their modes separated one from another this way.