Mini Nintendo Classics Keychains : 1 - Super Mario Bros : Inane leaping between side-scrolling platforms or a nailbiting race to rescue a princess? Probably both. 2 - Donkey Kong Jr : An arcade classic in which you help the son of an ape unlock padlocks by jumping between vines. As you do. 3 - Mario’s Cement Factory : This classic platformer sees the iconic tap-twiddler attempting to prevent containers of cement overflowing. Plumber? In a cement factory? Whatever.