While Space Panic may have indirectly influenced all subsequent platform games, Space Panic certainly directly influenced some very similar "trap-em-up" games at the time.[citation needed] These included some almost identical clones such as Acornsoft's Monsters (for the BBC Micro and Acorn Electron) and the Apple II's Apple Panic (1981) as well as the popular Lode Runner (1983), which looked very similar and used the basic premise of digging holes to trap enemies. Universal revisited the genre again with Mr. Do's Castle (1983) which incorporated and expanded upon many of the play styles explored in this seminal game.