Liberation Day is the sequel to Interactive Magic's previous release Fallen Haven. A tactical combat game with strategic management elements and an isometric perspective, this game also bears a strong resemblance to X-Com. Oh yeah, and the enemy is familiar as well: aliens!
The stakes are higher now, though -- this isn't the colony of Nu Haven you are defending, but Earth itself. Terrain types vary from arctic to jungle as you move through the progressive campaign that takes you across 4 continents. Multiplayer combat is also an option on a variety of skirmish maps. However, there is no mission designer or random scenario generator.