From the little-known developer Introversion, comes something a little different, something a little extraordinary and something that’ll make gamers tilt their head sideways to ensure they’re actually playing a modern PC game.

Darwinia is a virtual theme park inhabited by the Darwinians, an adaptive AI injected with virtual DNA, which can grow, learn and even have a soul. They were created by the genius that is Dr. Sepulveda, a fictional computer scientist (though clearly a close relative of Sir Clive Sinclair) in the 1980s. Now 20 years of work later, through the evolution of thousands of generations, they have become a new kind of life form. Unfortunately for these two-dimensional critters, a virus has entered the realm, and this is where the player stumbles into the game: at the deep end.

On first inspection the player could be forgiven for thinking they've booted an Atari ST or Amiga title, perhaps even further back for those who remember when chip-style music was considered an art form. Certainly the visual styling is very retro, similar in look and feel to Virus on the aforementioned systems, or Zarch as the similar title was known on the Archimedes. There are no massive, texture-mapped landscapes here, but that doesn't mean it's a bad-looking game; on the contrary, the spartan graphics suit the notion of the environment very well, giving the impression of a Tron-like universe, though perhaps far more futuristically avant-garde. Whilst it looks simplistic in design, it can be quite intensive in the CPU and graphics department on some of the game's levels.

The player takes the role of a system operator, and must create task programs that can then interact with the world; this is done via mouse gestures. Holding the ALT key brings up the task manager; the player can then draw the symbols that start the system processes, such as a triangle for squad units or a squared off 'n' for an engineer. At first it takes some getting used to, but there aren't very many shapes to learn, and it's pretty simple once this method clicks. There is a patch so that these gestures don't have to be used, but that's for wimpy system operators - it really isn't that difficult.

There are several areas of the fractal island-style world in Darwinia that need to be cleared of the virus infection, represented by a number of different beasts. The most common are centipede-like creatures, some of which are flat and die with a single hit, and beefier 3D 'pedes that break up into smaller units when shot. These aren't the only creatures that will have to be defeated: Spiders that crawl about the landscape, laying eggs alien-style also have their place in the game as do Generators that will fire pods to islands previously cleared of Virii. The movement of the virus units can appear to be rather haphazard and random, though some respond to being shot in a predictable way; that is, they will reverse their direction away from the source of hurt, and spiders will often gang up on a squad if spotted.

Once a squad unit is created, the enemy can be engaged, this is where the game switches from RTS to a more hands-on shooter approach; very similar in style to that of the '80s classic Centipede, but in a 3D environment. Moving a unit is a simple matter of left-clicking the area of the map to go to. Once the enemy is in range, holding the right mouse button fires the squad's weapons. Units need to be guided quite closely as the path-finding AI is about as good as myopic Lada drivers in Oxford's one-way system, and so will end up dead pretty quickly if not watched closely. This isn't really a big deal as there are no limits to the number of units that can be created, only to the number of programs that can be run simultaneously, but as they move very slowly considering the size of the maps, it can take time to get them in a position where they can get back into the action.

The engineering units require a little less guidance as these tend to be brought into play in areas that have already been cleared of the infection. The engineers are deployed to takeover buildings on the maps, such as the gateways to other maps, radar stations to transport squads to other parts of the landscape and incubators from where units can be deployed. All that needs to be done is point them in the general vicinity, and any structure they come across will automatically be converted; control of these is maintained even if the level is restarted. The environment is persistent, so leaving an area of the game and coming back to it later doesn't harm the progress that's been made.

Engineers can also upload research programs found on the maps; for example, in the first map an upgrade to the soldier units is available to let them throw grenades whilst shooting. These upgrades are essential in later levels so it is vitally important to capture all of them. Dr. Sepulveda also makes upgrades to his processes, for example, increasing the number of soldiers contained in a squad, thereby increasing their rate of fire.

As the number of concurrent processes is limited, units will need removing from the thread list via the task manager. The unit is selected with ALT-TAB and deleted with CTRL-C, making further reference to the fact the world is a running computer system, a consistency maintained throughout the game.

Each map has a certain amount of problem solving involved, though this isn't particularly cerebrally challenging. The player needs to work out which particular unit types or areas to destroy first, as certain areas will need to be cleared in order to reach the other islands in a level. The first map introduces you to these basic principles, and this is the mainstay of the rest of the game. A few new processes are made available as more levels are opened up, and some further enemy units are uncovered, but the game largely consists of moving units to where the virus is causing havoc, destroying the virus, capturing the buildings, rescuing the Darwinians and opening the gateways.

This does sounds very simplistic in its approach, but there is a good amount of tactical thinking and control required in order to defeat the game. The layered concepts of Darwinia evolve as the game progresses, requiring the player to learn something new with each level. Whilst this is hectic and fast-paced at first, later maps can take a good couple of hours to defeat; time which is barely noticed in its passing.

Darwinia is certainly unique in its visual styling, managing to mix a number of what might appear to be incompatible genres, set in a wonderfully realised game world to form a challenging and different game-play experience. Despite the fact some may find the concept of mouse gestures a little irritating at first, and the path-finding somewhat of a pain, those that persevere will be rewarded with some solid interactive entertainment.