Savage Moon, from little known Bristol developer FluffyLogic, is about as good as it's going to get for just over six quid on PSN. It's also perhaps the most aptly named game ever. All 12 levels are set on moons, and it's absolutely savage. There you go. End of review.

Only joking. There's more to it than that, of course. It's a tower defence game, at its heart, with heaps of strategic depth and lashings of real-time resource management, but there's a twist. A gruesome, gory, twist. You're defending your moon base from alien insects, called Insectocytes. Thousands and thousands of the creepy, disturbing, disgusting, Insectocytes, who are all hell bent on worming their way towards your moon base and bringing it down in a soul-destroying boom. Think Starship Troopers spliced with PixelJunk Monsters and you're halfway there.

Savage Moon is structured in classic tower defence style. You begin each mission with a set number of credits with which you're able to buy and lay down turrets in anticipation of the first wave of horrible beasties. The turrets you place down will automatically attack any target that encroaches on their firing radius. At the beginning of each game, you only have basic machine gun turrets available to you, but you're able to spend money researching new technologies and upgrading existing technologies so you can better cope with the varied bug types that come at you. With the thumb sticks you're able to swivel the camera in a somewhat constricted fashion, and with simple presses of the X button, either on open terrain or on your existing turrets, you're able to quickly and easily access all the game's menus and cope intuitively with the waves of bugs.

Survival tip number one: Kill bugs to earn cash.

You gain cash by killing bugs. Simple as that. So as the waves of aliens come and your turrets dispatch them, your credit count goes up. You're able to see what alien type is coming in the next wave, too, which means your hard-earned cash will be spent adapting your defence to whatever bug's about to monotonously snake its way towards your base. You need to quickly research anti-air turrets, for example, because more often than not flying bugs will emerge from purple tunnels built into the asteroid rock in the second or so wave, and the basic turrets won't cut it against them. There are mortar turrets, which fire bombs at range, and laser turrets, which are slow firing but strong against well armoured alien bugs, to research as well, meaning there are plenty of units to play around with.

There's more, too. You're able to lay down blocks, which act as path blockers, forcing the alien horde to take long winded routes towards your base. This gives you more time till they reach your precious innards, of course, but it also exposes the aliens to your turrets for longer, which is invaluable, especially when faced with fast moving bugs and tank bugs that absorb loads of damage. Only problem with this strategy is that the bugs can attack and destroy your defences, which makes repair turrets essential.

Savage Moon's got a surprising amount of strategic depth, especially compared with other recent tower defence games on the market. You have to quickly size up a map, work out where the bugs will come from and the path they will take towards your base, and lay down turrets appropriately. Because you can see what bug type is coming in the next wave, a knowledge of what defence type works best against what bug is essential, as well as smart placement so you're not wasting cash on needless turrets. You're encouraged to work quickly, too, because doing so will allow you to advance the wave of aliens and give you a credit bonus. You can also adjust the emphasis of your strategy, increasing the amount of cash you earn from killing bugs, beefing up your armour or increasing the amount of damage your turrets do, or a balance.

While the environments are bland, the art style fits the bleak tone perfectly.

It all makes for a surprisingly addictive but brutally difficult tower defence game. It's very, very hard. Each wave gets increasingly difficult to cope with, as you'd expect, but by the third or so moon, things get a bit too hectic and it's a bit too early on in the game for that to happen. The tutorial and overall production values aren't up to much, either, but you can't really complain when it's this cheap.

Most impressive, however, is the game's overall depressing tone, and it's the art style and audio which contributes most to this. The graphics are minimalist in the extreme, with little to warm the soul. It's a harsh world out there mining moons and surviving against swarms of alien bugs, and the art style rekindles memories of Introversion's similarly bleak Defcon. While the environments are drab, the bugs themselves are well animated and really catch the eye. If they weren't such gits you'd probably admire them. Savage Moon won't win any awards for its looks, but FluffyLogic has done a good job of coming up with a style that reflects the context of the tower defence gameplay.

The audio is best though. It's horrendous, but in a good, uncomfortable way. The shrieks, clicks, croaks, ticks, gurgles and cries of the bugs, not only as they emerge from their pits of doom but also when they're blasted into oblivion by your turrets, are just brutal. And the sound's relentless. With any luck you'll be killing a hell of a lot of bugs so you'll be hearing them constantly. One of them particular is especially awful on your ears, the kind of noise you'd expect a possessed pig to make if it were ever torn to shreds by an automatic rifle.

The noises the bugs make when you kill them are brutal.

And it's all complimented by a wonderfully depressed soundtrack, reminiscent of the original Interplay Fallout games. The solemn, cold and lonely beeps and boops of each mission hammer home the bleakness of what you're doing.

Savage Moon won't be for everyone. It certainly won't be for anyone who doesn't first and foremost enjoy the tower defence genre as a whole. It's great value, offering 12 levels and online leaderboards. The fact that there's no multiplayer, locally or online, is a criticism, as are the quality of the environments, which are a bit bland, but otherwise Savage Moon offers a unique and refreshing counterpoint to the cutesy tower defence games the market seems to be flooded with at the moment.