Mercury Meltdown, like its nearly excellent predecessor, is that most gamey of things: a perfection puzzler. Played out a bit like a triathlon where you have to do everything at once, the idea is to manoeuvre a little blob of liquid metal around a maze suspended in the sky, without letting any of the blob slip off the side, while collecting little sparkling stars, and all within a time limit.
You don't have to do all those things at once, but your final score for the level will probably be higher if you do. Either way, you end up working through each level as many times as it takes to get everything squared away, at which point the little test-tube that represents the level you're on in the "lab" hub will fill up, have a star stamped on the front and receive a cork - with a golden stopper for those of you who can top the scoreboards, too. You won't want to give up on a level until you've made it, and then you'll load up the next one and do the same because you can't stop. In that sense, it's probably more of a simultriathlon for nandrolone addicts (although, in this case, the lab results are points of pride, obviously).
The first Mercury was, by the developer's own admission, rushed to meet the PSP's European launch deadline, and as a result some elements were a bit wonky. The controls were, and still are, absolutely great - the analogue nub gives you excellent fine control of the mercury blob, which is governed by consistent physics. But the camera, which could only pivot round four points using the face buttons, often made it hard to get a good view of the action, while a combination of frustrating difficulty spikes and an unforgiving structure meant that progress sometimes ground to a halt. It can only have been a select few who saw all of the game's 84 levels.
Work on the sequel appears to have been a bit less hectic though, because Ignition Banbury (formerly Awesome Studios) has for the most part sorted out those problems, has doubled the number of levels, has streamlined the goals, has gotten rid of some less enjoyable or redundant aspects of the level designs, and has even had time to put together a range of unlockable party games. Most importantly, it's made a game out of which people at both ends of the skill spectrum will get a lot more fun.
The new "lab" hubs give you instant access to 16 levels. If one proves too difficult, you can play the next one instead, and new labs are unlocked by transporting high percentages of mercury to the goal, which fills up a mercury meter on the hub screen, rather than by having to do all of the levels perfectly. Party games, meanwhile, are unlocked by collecting those stars I mentioned, of which each level has a small number located in difficult-to-reach positions; these then fill up a star meter. Each lab also has a final, really hard unlockable 17th level if you do all the others
The addition of a free-view mode, located on the Select button, means that you no longer have to rely on the beginning-of-the-level flyby to try and work out the route to the finishing line plate, too. The camera remains the same, but the design of the levels has been more carefully considered so that you're less likely to come across situations where you can't get a proper view of your blob. You're allowed to keep playing after the time runs out too, as even the smallest globule of mercury successfully transported to the goal results in completion; it might not do much for your mercury meter back at the hub, but it does give you something to be satisfied about.
And even if Ignition Banbury hadn't done all the good stuff in the last two paragraphs, the game would still be better because the level design is much more consistent, on a difficulty curve rather than a difficulty scatter-chart. The fact that they did do all the things above merely puts Meltdown even more comfortably ahead of the first game.
Level design is judged so that it usually takes just a few seconds at the start to figure out your route, and from then on it's about being dextrous. Variety in level design is extremely pleasing. One level might be about manoeuvring your blob around a flat maze, timing your movements to dodge little thrusting ploughs that aim to throw you off, squeezing along the occasional narrow ledge and carefully flowing across undulating surfaces to the goal. The next might be about splitting the blob into two parts, running them both into little colouring stations, guiding them along parallel platforms and then safely combining them to go through a gate that demands the mixed colour - with a handy colour chart permanently installed in the top right to help. The next one might be more helter-skelter, with conveyor belts moving up the side of a wall, the idea being to ride one to the top and then fall down to the next one.
There are new elements to keep things interesting. As well as mixing colours and activating switches to open gates, there are split goals, which have to be hit simultaneously to end the level. Sometimes these are colour-coded. There are bounce pads, too, and control platforms that move in the direction of the edge you're closest to, and crumble blocks. There are different mercury states - little translucent cubes transform your mercury into a hardened sphere, which can then run along little metal tracks that the blobby mercury couldn't cross, or make it runnier, so that it moves faster but breaks up a lot more easily.
The consolidation of three different types of goal into one level has improved the game too. The original had speed, puzzle and mixture levels, but in effect these are all opt-in mixture levels. And the consolidation of other elements helps too - teleporters were always the same as those suction cup things, really, so now there's just one type. And there are less recurring themes that make you groan. Split levels, levels about speed, conveyor belts, levels about hugging surfaces - they're better designed, so it's less frustrating. The only ones that turn me off are the levels that invert gravity for a bit, reversing the controls as you move along the underside of a platform, and the ones that feature little wandering AI cubes that need to be blocked into taking a path to a critical switch. Fortunately, these things are in the minority, and some of them are pretty good anyway.
What there is instead is highly addictive, and as before there's even further to go for the truly dedicated, with shortcuts to eke out that help you find phenomenally high scores. The first time you manage to cut out half a level through some inconceivable feat of nimble-fingered wizardry, the option to save ghosts or entire replays (both just two or three hundred kilobytes) will come in handy. Ghosts can then guide you on future attempts, while replays load into the replay-viewer in less than ten seconds, allowing you to manipulate the camera independent of the on-screen action too - perfect for showing off to friends, with files small enough to email. Sharing these directly doesn't appear to feature, but you can introduce your friends to the game by uploading a demo version to their PSP, while downloadable levels will be made available in future.
Actual multiplayer can only be achieved with two UMDs (sadly not something we could try), but remains much the same - racing the ghost of the other player, with the addition of a few power-ups to shake things up. The unlockable party games are also primarily enjoyable in multiplayer, but you can play against the AI too.
They're a bit throwaway played alone, mind, although Paint, which involves covering as much ground as possible with a snail-trail while an opposing player does the same, is quietly addictive. Rodeo is about hanging onto a surface while fans try to blast you off, Shove is a slightly disappointing game of curling with awkward controls, Race is a fairly simple racing game, and Metrix is quite an arresting little three-in-a-row puzzle game where you create your own puzzle shapes using a mechanism a bit like an ice cream dispenser married to an ice cube tray. Each has a healthy quota of levels.
Even without these things, though, Mercury Meltdown would be a brilliant sequel, improving on the original in almost every way. Even the cartoonier graphics and cel-shaded blob, which proved contentious when it was first announced, are intelligently composed - able to convey important things like surface gradients intuitively - and with amusing unlockable mercury skins too. Not only is Meltdown bigger and better to look at though, but it offers new and compelling scenarios, and proves more appealing to new players as well as a more consistent proposition for hardcore fans - not everyone's going to be able to beat the incredibly punishing latter levels, but there's still hours of fun to be had beforehand. Overall it's hard to fault, really, and I really hope it finds a wide audience.