Sony's Move controller is undeniably an impressive piece of technology, but the software so far hasn't quite shown how impressive. Sports Champions is half of a brilliant game, Start the Party is a trumped-up EyeToy title whose main distinguishing feature is that it works properly - and the less said about the mess that is Kung Fu Rider the better. In the absence of a genuine killer app, it's been left to this PSN title to show the big boys how it's done. As a demonstration of Move's capabilities, Tumble is pretty hard to beat.
Let's get the obvious question out of the way: yes, it looks a lot like Boom Blox, but it's not really much like it at all, apart from the occasional destruction challenges which are basically Boom Blox if it went to finishing school. There's nothing as uncouth as throwing stuff here; instead, you're asked to demolish a pristine structure using well-placed limpet mines. (It's a finishing school with access to military-grade explosives, obviously.)
Tumble is actually quite unsuitably named, since it's more about building things up than knocking them down (though it's probably for the best that Sony didn't call it Erect). At first, you're asked to build a structure using blocks of various shapes, sizes and textures. The idea is to stack them to a given height - or rather, three given heights, representing bronze, silver and gold medals.
There's a fine balance between ensuring your construction is structurally safe and making sure it's tall enough with the limited number of blocks you're given. Should you hit the bronze medal height, you'll get a three-second countdown during which your structure must remain intact. It can still be wobbling when the timer hits zero, but as long as no blocks hit the ground, you'll pass, and move onto the next challenge - like WiiWare game Art of Balance, for the seven people that played it.
Most levels offer additional objectives once you've earned a gold medal, such as having one of your blocks pass through a hard-to-reach target, or completing a stage within a strict time limit. Get enough medals on one zone and you'll unlock the next. It's fairly simple in the first couple of zones, with most gold medals within the reach of the average player. Then it all goes a bit Krypton Factor.
That's because Tumble is as restless as a wonky tower of polystyrene and balsa wood, introducing new features or level types every few stages. One minute, you're stacking blocks or squashing them all together on a small platform, the next you're refracting beams of light through coloured orbs by positioning mirrors and colour filters. The starting platform gets gradually smaller, then it spins, and then it slopes, and bonus stages have you solving simple maths problems or completing a jigsaw. Others ask you to reach a certain height using just a handful of awkwardly shaped pieces. And that's when the game's not actively trying to knock your tower down with moving metal blocks or gravity wells or earthquakes.
In some of the challenges it seems to revel in being as difficult as it possibly can, throwing out a perfectly square block just when you'd left a space for a triangular piece, or giving you huge, heavy rubber rectangles when you've got nothing to balance them on. It's like waiting for one of the straight pieces in Tetris. And as if to invite further comparison, a few levels introduce Tetrominoes, with one level - the evocatively titled Russian Limbo - asking you to slot them together as tidily as possible to fit under a metal bar positioned at a dangerously low height.