Greener than Luigi and sporting a longer tongue than Mario, Yoshi is no longer a member of Nintendo's B-list. He's now a hero in his own right. In his latest Game Boy Advance adventure, Yoshi's Topsy-Turvy, Yoshi is pitted against Nintendo supervillain Bowser, who, for some reason, has taken to turning the egglings that inhabit Yoshi's Island into apples. Further complicating matters is Hongo the great book spirit, who decides to trap Bowser in a pop-up book. But in doing so, he consigns the whole of Yoshi's Island to the same fate. It's an unusual storyline for sure, and things only get stranger as Yoshi attempts to play through the pop-up book's various chapters en route to a confrontation with Bowser on the last page.
Far more intriguing than Yoshi Topsy-Turvy's storyline is its "tilt control" system, which lets you control the direction of gravity in the game simply by tilting your GBA to the left and/or right. The tilt control plays a large part in all of Topsy-Turvy's 52 levels, and while its uses are occasionally quite clever and challenging, they're often uninspired and require little or no skill. The most challenging portions of the game are invariably those that require you to make jumps between platforms (or even vertical walls) that would be impossible under normal gravity conditions. Less challenging, though initially more interesting, uses for the tilt control system include gaining height on halfpipes, rolling out carpetlike platforms, swinging demolition balls into destructible blocks, and controlling the trajectory of cannons that Yoshi is shot from.
Whereas most areas of Yoshi Topsy-Turvy simply add the tilt mechanic to an otherwise quite conventional 2D platformer, there are a number of areas you'll play through using the tilt controls almost exclusively. The majority of these areas are those in which Yoshi is magically transformed into a ball, a balloon, a boat, or a ship. What's the difference between a Yoshi-boat and a Yoshi-ship? Only one of them can jump. The transformation levels are some of the most enjoyable in the game, but like everything else in Topsy-Turvy, they're extremely brief and manage to become repetitive.
Yoshi Topsy-Turvy is divided up into six chapters, each telling the tale of a different spirit, whose objectives you'll have to complete on the majority of that chapter's courses. Objectives in the game include reaching the end of a level within a certain time limit, collecting a certain number of coins or apples, and destroying or managing not to destroy a certain number of enemies. Each course will have either one or two objectives you'll need to complete to get a silver or gold happiness medal, and you'll need a number of medals in each chapter before you can progress to the next one. Earning happiness medals also lets you spin a bonus wheel, which in turn lets you play one of three different bonus games, which in turn gives you an opportunity to earn extra coins toward your next extra life. The bonus games are overly simplistic, unfortunately, and some can actually be completed successfully in under three seconds.
Despite comprising four distinct areas each, the 52 courses in Topsy-Turvy (including two Bowser encounters) are also disappointingly brief, for the most part. Most can be completed in just a couple of minutes, and many are actually played against time limits of two minutes or fewer. It's also worth noting that you'll only need to earn happiness medals on 36 courses to get to Bowser. And once you've done that, there's very little incentive for you to go back and complete the others.
The visuals and audio in Yoshi's Topsy-Turvy are every bit as charming as those in previous Yoshi games, and if it weren't for the fact that they're just as repetitive as the gameplay, they'd be very difficult to fault. Yoshi's Topsy-Turvy, then, is fun to begin with, but it manages to become repetitive long before you finish it--which might take you only five or six hours. For what it's worth, the game's difficulty curve is nigh perfect, and after breezing through the early chapters, you'll almost certainly struggle to beat some of the later courses on your first couple of attempts. It's not a bad game by any means; it's just a repetitive and disappointingly short one.