Yoshi's Topsy-Turvy (released as Yoshi's Universal Gravitation in Europe as Disney owned the Topsy Turvy name as a song in their The Hunchback of Notre Dame film) is a game for the Game Boy Advance.
The Spirits sealed up the entire island into a story book called the Forbidden Pop-Up Book. Now Yoshi must meet the challenges put forth by the spirits to earn a chance at fighting Bowser and saving the island.
In this game, Yoshi's physics and controls are notably the same, but the new mechanic of this game is that player can tilt the Gameboy Advance to change and move objects; this new mechanic is the main aspect in the game.
By tilting the Game Boy Advance, the environment around Yoshi is rotated to knock over enemies, swing pendulums, and help Yoshi run up walls and leap huge pits. All of Yoshi's Island is trapped in a storybook, and only by meeting certain chapter-specific challenges can a chapter be completed.
At the time of its release, most critics thought of Yoshi's Topsy-Turvy as a mediocre title. Craig Harris of IGN said the game was too short, and most critics thought the other Game Boy Advance game to use a tilt sensor, WarioWare: Twisted!, was a better example of tilt-sensing technology in video games. 1UP.com's Jeremy Parish called the tilt controls "graceless and clumsy" and the character animations "choppy", concluding that it was a "mediocre" and "boring" game. GameSpot's Justin Calvert thought the tilting worked alright and enjoyed the graphics and difficulty curve, but overall found the game to be "repetitive and disappointingly short". Game Informer enjoyed the tilt sensing, calling it a "neat" and "inventive" mechanic that "breathe[d] new life into the [platformer] genre", but was disappointed by the level designs, which were mostly "pretty standard fare."
Another point that is often criticized is that, due to the tilt-sensor and its orientation, the game can only be comfortably played on the original Game Boy Advance, while it is confusingly mirrored on the Game Boy Advance SP and not playable at all on the Game Boy Player. However, the game includes a menu screen at startup in which the player can select the handeld system they are using: either the original Game Boy Advance, in which case the game cartridge is inserted from the top of the system, or the Game Boy Advance SP, Game Boy Micro, Nintendo DS, or Nintendo DS Lite which all feature a bottom loading slot to insert the cartridge. Selecting the corresponding cartridge slot orientation at this menu eliminates the mirrored tilt sensing so that the game can be played on any of those devices. The player can also re-calibrate the tilt sensor to fit whichever game system they use.