Tearaway Is Designed for the PlayStation Vita Sony Computer Entertainment America LLC Tearaway This game, designed by Media Molecule for the PlayStation Vita, breaks down the fourth wall, making the player's face the virtual sun. Some music is made for violin and unimaginable for trumpet. Other pieces are best on piano, worst on drums. Some video games are also like this, designed particularly for a particular instrument. An oddity called Tearaway, recently released by the British studio Media Molecule, is one such game. It enjoys the fortune and suffers the misfortune of being perfect for the unorthodox and not very popular hand-held PlayStation Vita. Through its use of the Vita, Tearaway marvelously breaks the fourth wall. It's a video game that, as few before it have done, presents a world of virtual people who seem aware of the person playing the game. The Vita may not be a smash commercial hit, but Tearaway is a game that finally justifies the machine's existence almost two years after its introduction in the United States and is inconceivable on any other platform. The Vita has the dimensions of an oversized cellphone, about a half-inch thick and meant to be held horizontally, gripped at its short ends. The five-inch screen on the front is touch-sensitive. So is the black plastic panel across the back. One of the Vita's cameras points out from the back, and the other is aimed at the player's face. Unlike a smartphone, the Vita has two little joysticks and some buttons that allow for a conventional style of play. The Vita's left stick is used to move Tearaway's hero or heroine through a virtual world. The buttons make this character, a "messenger" known as Iota or Atoi, depending on gender, attack or jump. The messenger's world appears to be made out of construction paper. Grass seems to made from ragged green paper, partly glued down and rolled up. Hills might as well be pinched and molded mounds of brown paper. The messenger, too, looks like a paper doll. Other games on other systems can present the kind of virtual arts and crafts seen in Tearaway. But they can't involve the player the way the Vita game does. The sun in the messenger's world is a ring of rays that surround a live video feed of the player's face, streamed in through the Vita's front-facing camera. The ground on which the messenger walks is fragile and pliable. In something of a technological magic trick, players can tap the tips of their fingers on the Vita's rear touch panel to pop the messenger into the virtual air or to seemingly poke their fingers into the messenger's world to move things around. The fourth wall is broken from both sides. We don't just enter the game's world; it appears to reach out into ours. As players progress, they unlock access to online directions for cutting and folding colored pieces of paper that resemble the characters in the game's world. The idea is that by doing so, the player will welcome the critters of the messenger's world into ours. All of this is quite clever and feels right on the Vita, a machine that Sony seems to be turning from a portable multiplex to a portable art-house theater. It is nevertheless the least popular of the major home or portable gaming machines sold in America by Sony, Nintendo and Microsoft. System-defining games are among the rarest breed of video games. Most games run reasonably well on a variety of consoles or don't use the features of the machine they're made for in a special way. The exceptions, however, have been excellent. A powerful processor and the novel analog joystick of the Nintendo 64 enabled the remarkable Super Mario 64, which used the technology to translate a traditional, two-dimensional, left-to-right running-and-jumping game into three dimensions. It was a breakthrough as fundamental to gaming as the addition of sound was to cinema. The voice and stylus-controlled Brain Age was played on a clamshell, two-screened Nintendo DS, held sideways like a book. Brain Age was marketed as a game that would keep its player's brain youthful. It was joined by a dog-training simulator called Nintendogs that used the pioneering touch screen and microphone of the DS to enhance the sense of connection to the virtual animal. Those two system-definers made the DS a huge hit. In theory, a system-defining game should sell its system. A problem for Tearaway and the Vita is that this game feels mostly like a clever art project. There's no disrespect intended, but the game was made for a machine that was designed to present console-quality gaming on the go and has, so far, offered the kind of first-person shooters and racing games that look nearly as good as the ones on a PlayStation 3. Lately, Sony has shifted, promoting the Vita as a vessel for more personal, quirkier games. Is that a viable way to promote a $200 device that is not also a smartphone, a tablet or a portable machine that plays popular Nintendo franchises? A struggling system can certainly have a great game that is perfectly tailored for it, and that is what we have with Tearaway. It's a piece of music well worth playing. But you'll have to buy an obscure instrument just for it. Tearaway, developed for the PlayStation Vita, is rated E (Everyone) for mild cartoon violence. Stephen Totilo is the editor in chief of the gaming site Kotaku.com.