An unsung hero in Sci-Fi RTS gaming.
This is due to the fact that Earth 2150 games have more depth. There is research to do along a robust research tree, branching into weapons, armor, and chassis types. There is resource allocation to do, not just to build units, but to fuel your research to upgrade and develop new units and to further the campaign goal of getting off the planet.
The game play itself is much like any other RTS, but add things like ammunition depletion and you find yourself thinking more like a real commander running operations in the field, logistics being an area seldom touched upon in RTS games.
You can customize both units and buildings with the fruits of your research, and with three distinct factions you have many customizing options.
You also get to play through some 50+ missions, a feat unheard of in latter day RTS games.
You get a full 3D environment with full camera views in any direction, and while the graphics are showing their age they still compare favorably overall.
Perhaps all this detail and layering of strategies is what held this game back, it just didn't appeal to those who just want to build up armies and rush the enemy as quickly as possible.
Earth 2150 is a more thoughtful game, as you need to think more realistically than one normally does playing games of this genre, and so this is both it's strength and unfairly a weakness.