Ok there's this game I'm desperately trying to remember the name. I remember just about everything about it, except the name so here it goes:
It's definitely a windows game (probably 98/not DOS)
It's a space deathmatch kind of game;
You just click with the mouse to move;
It's 2D and pretty simplistic;
There's a grid and you basically just fly around, there are planets with people and without people;
The ones without people you can gather resources from; the ones with people you can sell resources to and buy equipments;
The objective of the game is to get X amount of kills;
As a planet gets stronger it develops a shield around it making it harder to kill it.
Some of the weapons are lasers, but the weapons that I can best remember are the plague bomb, which shoots this little green swarm and when it hits the planet it slowly kills the population, the icon for it is redish and looks like one of those "biological danger" and then there's the nuclear bomb which is slightly like the plague bomb but is yellow and blue.
If I'm not crazy one of the ships you can use looks like a yellow angry smiley face.
I believe you can take people from the planets with people and take them to the planets without people.
As long as the planet is yours, it stays green (i think) and will shoot enemy ships, and if it's not yours it stays red (i think) and it will shoot you.