This may seem ludicrous but you are a jet-pack wearing space-man in charge of maintenance ladders in a green house full of aphids (which incidentally, are blue) and a variety of flowers. You have to shoot these aphids (of course, these are the lethal variety and must not be touched) with your laser and build up the maintenance ladders whilst keeping an eye on the phloem level of the plants. When the phloem level gets too low, you have to drop your jet-pack, wear a flower-nutrient pack and feed the plants.
The storyline may seem a trifle ridiculous but the game itself is quite good fun to play. The characters are large and there's minimal flicker. When the deadly aphids are shot down by your laser fire, they disappear accompanied by a lovely crunchy explosion. I felt that a bit more effort could have been put on the animation of the characters and a touch of music would have been nice but overall, Microcosm is an enjoyable game at an affordable price.