Wouldn't it be great if Super Monkey Ball Deluxe got released on PSP? Until that happens, we'll have to make do with Mercury. It's a puzzle game in which you tilt a board to guide a bead of quicksilver around a maze. Lose too much mercury or miss the time limit, and you're out.
Put like that, it sounds fairly simple. But having a blob of liquid metal as a hero means all manner of funky things can happen. Your bead can split up into smaller beads, for example, and tilting the level moves them all around. Get too many of them on the screen, and the human brain spontaneously implodes from the mind-hurt of trying to control them.
You can also colour your blobs in different hues, allowing them to open special doors. Chuck in enemies, moving parts and a blocky sentient obstacle called Stan, and you've got something more akin to the corridors of Hell than a PSP puzzler. The mercury itself looks good - apparently 90% of the PSP's processing power is used to create it - and the levels aren't exactly ugly, but the overall game presentation is bizarrely 1980s - think squishy, coloured fonts and occasionally clunky menu systems.
Mercury had our opinions sloshing back and forth like, well, mercury. The gameplay is undeniably a new thing in the world... but not necessarily an amazing one. Once you get used to the controls you'll be fine... but all too often levels seem like chores rather than challenges. As much as you might find yourself cursing the screen... you'll still end up spending hours on the frequently frustrating levels. Multiplayer is a giggle... but why do levels take ages to load? It's a mixed-up title, to be sure, and not everyone will agree about its charms. Give it a go, then, and see for yourself.