collect items and powerups that can come in handy for different situations, and give the main character new abilities for overcoming adversities. Most games of this genre consist of multiple levels of increasing difficulty, that may also be interleaved by boss encounters, where the character has to defeat a particularly dangerous enemy in order to progress. Usually the level order is pre-determined, but some games also allow players to navigate freely throughout the game world, or may feature different paths to take at certain points. Simple logical puzzles to resolve and skill trials to overcome are another common element in the genre. A more modern variant of platform games (generally 3D scrolling), called "runners", have the main character always moving forward at high speed while the player must direct it properly to not make it fall or crash against obstacles, and manage to reach checkpoints on time. Due to the relative simplicity of the controls, this kind of game works well on mobile devices and has become popular in recent years. Naming Various names were used in the years following the release of the first established title in the genre, Donkey Kong (1981). Shigeru Miyamoto originally called Donkey Kong a "running/jumping/climbing game" while developing it. Miyamoto commonly used the term "athletic game" to refer to Donkey Kong and later games in the genre, such as Super Mario Bros. (1985). Donkey Kong spawned a number of other games with a mix of running, jumping, and vertical traversal, a novel genre that did not match the style of games that came before it, leaving journalists and writers to offer their own terms. Computer and Video Games magazine, among others, referred to the genre as "Donkey Kong-type" or "Kong-style" games. "Climbing games" was used in Steve Bloom's 1982 book Video Invaders and 1983 magazines Electronic Games (US)—which ran a cover feature called "The Player's Guide to Climbing Games"—and TV Gamer (UK). Bloom defined "climbing games" as titles where the player "must climb from the bottom of the screen to the top while avoiding and/or destroying the obstacles and foes you invariably meet along the way." Under this definition, he listed Space Panic (1980), Donkey Kong, and Frogger (1981) as climbing games. In a December 1982 Creative Computing review of the Apple II game Beer Run, the reviewer used a different term: "I'm going to call this a ladder game, as in the 'ladder