The game's first episode is lava based. Lava spews from volcanoes and gaps in the environment, spilling out and across the stages, burning everything in its path, including workers and the planet's hostile creatures. When lava meets water, it cools, turning into a rock you can destroy with laser fire. So, if a worker is trapped underneath lava, to rescue him, you need to pour water on it, turning it into rock you can shoot through.
The element-based gameplay and puzzle-solving is clever, but the superb physics unequivocally steal the show. The fluid dynamics really are a joy to behold. Lava flows spectacularly, which is a weird thing to say of a 2D game. Water cascades with a current that drags your ship. Lava is thicker and weightier than water - your laser fire doesn't travel through it as easily. Water barely affects laser fire at all. For a downloadable game, it's superbly realistic. Sometimes, you'll unleash lava and water and it'll come together so beautifully, that you'll find some place safe to sit back and enjoy the show.
Some of the later stages, however, offer no such luxury. From half way through the second episode onwards, the cavernous stages require careful movement and clever environmental manipulation to save enough workers to open the exits. You're able to grab objects that act like sponges, absorbing water and lava, and then empty them in other areas - they explode like water or lava bombs than can do as much damage to your ship as they do to the environment. Laser beam trajectory can be altered so beams bounce off of reflectors, melting ice and destroying enemies. Gas flows can be set alight, destroying vulnerable rock as it burns. Some enemies bore through the environment as they try to destroy you - leading them a merry dance is a useful way of opening up new areas. Eventually, you'll gain access to Water and Magma suits, which allow you to fire your own water or lava streams (the lava cannon in particular is brilliant). These suits also give you a special claw that can be used to pull ice formations apart. And, even later, you get access to an Inverter Suit, which allows you to enter the lava itself (the third and final episode adds another element to the mix, one best discovered yourself).
It is when Shooter combines all of its elements that its best nuances are revealed, and is most challenging. Sometimes you'll find yourself head-scratching for over half an hour, trying to work out how to melt this particular bit of ice, or reach that particular worker. Shooter never overwhelms you with mechanics, but towards the end of the game, it does expect you to have been paying attention.
Shooter's only real problem is that it feels too short, even at £6.29. The three episodes shouldn't take longer than four hours to work through. The game feels like less value, however, when you consider replayability. Once you've worked through all three worlds, the only motivation to go back and replay the stages is to improve your overall score or to lower your individual stage completion time for the online rankings. But speed runs don't sit well with Shooter's more considered gameplay. It's more enjoyable to try and complete every level without dying, rescuing every worker, eking out all the off-screen secrets and nabbing the hidden treasure. It might not be particularly flashy, but it's rewarding nonetheless.
And the two-player co-op mode, while fun by virtue of playing with a mate, the game isn't designed to make the most of it. There are one or two nice co-op features, such as being able to rescue your on fire chum by grappling him and dropping him in water, but there's nothing that can't be done on your lonesome. And, somewhat surprisingly, I quite preferred playing the game on my own, holed up in intense, solitary confinement, forehead creased in concentration.
PixelJunk Shooter is an enjoyable, quirky game that's yet another successful entry in the PixelJunk series. And, as with all the PixelJunk games, it's right up PSN's street, a service that's fast becoming the home of the weird and interesting. There can be no doubt that the game's over too soon, but the journey is still worth travelling. When water meets lava... Well, that's worth the asking price alone.