Let's be honest: there's something faintly urethral about the stuff that turns up at the bottom of the sea. Am I floating around in the balmy deeps of the Pacific, or am I, you know, busily swimming through someone's groin? It all gets rather hard to tell down there, where the fish have long tails and weird heads, and the water grows cloudy with minerals.
In the hands of another developer, then - oh, let's try and imagine that PomPom had a go at it - Lightopus could be properly disgusting. With Appxplore and Bulkypix in charge, though, it's pretty, evocative, and rather dreamy instead. It's a quick neon safari, or a glimpse into a stylish and quietly orderly aquarium.
Lightopus is a zone-inducing arcade game based around collection and simple combat. You're the last of your kind - don't panic, I'm still talking about the game - and your job is to swim through an underwater abyss collecting little tadpole children, presumably so you can go and thrive and multiply somewhere dark and warm and then spill out horrifically when I duck under my sink to see what's causing that blockage. Your children are called bulbies - still talking about the game - and once you've collected them from little pods scattered around Lightopus' pretty, rather open-plan arenas, they'll follow along after you in bright, shimmering swarms.
Your aim is to gather a certain number of bulbies in order to escape from each zone. That would be a bit tedious by itself, of course, so there are also enemies sloshing around who want to finish you off for good. You can knock them about with your tail or do them in with a range of power-ups, but your most successful means of thinning their ranks is setting your wriggling little children on them. Do not do this at home.
Bulbies chew through baddies like they're a pack of Oreos, then, but in doing so they tend to take heavy casualties. At the heart of Lightopus is a balancing act, in other words: collect, defend, and move on while you still can. If you stick around to try and raise your score in each zone, you risk getting trapped there, but, come on, a few more seconds couldn't hurt, right?
It's quite a busy game at times, but the dreamy setting, the graceful sense of movement and the nice tap-to-steer controls (there's a virtual joystick option, too, but I wouldn't bother) can render it all strangely hypnotic. It's not rare to find you've zoned out a little too much, in fact, and have let your health whittle itself away in chunks before, woozy from the calming visuals, you fumble yourself into the presence of a massive boss and things start to go very badly.
Keep an eye on your surroundings, though, and you'll be able to string play sessions together for hours. Lightopus feels like a modern, stylish, and rather organic spin on a very old arcade game design - something that would exist midway, say, between Blockade and Berzerk - and that can only be a very good thing indeed, if you ask me.
App of the Day highlights interesting games we're playing on the Android, iPad, iPhone and Windows Phone 7 mobile platforms, including post-release updates. If you want to see a particular app featured, drop us a line or suggest it in the comments.