A good, original game which is a bit too easy for its own good
Although there are bits and pieces of gameplay that you may be familiar with, such as the gesture system similar to Black & White's spellcasting, for the most part Darwinia feels like a game that you haven't played before.
You play the role of a computer user forced to defend the artificial world of a researcher from a nasty virus. At your disposal are a single attack unit (which gets supplemented a bit later in the game with a tank/turret unit) which can be upgraded to carry various weapons, engineers to capture buildings, and the mostly useless but remarkably endearing Darwinians, who behave much like lemmings with the death wish turned down a notch.
Although your engineers will automatically pick up souls from destroyed viruses, which can then be used to create more Darwinians, and your soldiers fire their basic weapons at nearby foes, the creatures of Darwinia are not a bright bunch. They require constant attention and cannot be relied upon to win the day without you, which is just fine because you can have at most five units created at a time, and there are no resources required to build the units anyway. As a result, the gameplay in Darwinia focuses heavily on tactical combat, and I rarely found it useful to have more than a single unit of soldiers under close control with another sitting idle nearby as backup should the first unit be destroyed.
Sadly, like most strategy games, the gameplay does tend to grind somewhat after a while and because it is impossible to run out of resources, victory is always a matter of time which makes the game feel far too easy. While you may never feel that boiling rage of not being able to finish a mission, nor is there any huge sense of accomplishment when a mission is completed.
The graphics in Darwinia are something of a highlight, rendered as they are in a mix of ridiculously low polygon models without texturing and simple 2D sprites. The sound is similarly retro, as if 32-bit sound were being used to reproduce the PC speaker sounds of old. The game manages to look and sound exactly as you would expect a digital world under attack from a computer virus to look and sound, and serves as an example that bump-mapping isn't the only way to make a good-looking game.
If you like strategy games, think back wistfully to Sacrifice (and all strategy gamers should), or just want to take a break from killing Nazis, then Darwinia should hit the spot. Especially considering it's available over Steam and at a budget price.