The RTS staple of harvesting resources receives new life with Earth 2150. In a smart design move, harvesting is given a dual purpose. Players must divide their resources between building armed forces for the present, and saving for a future. The world of Earth 2150 is extrapolated from our own, and the three surviving factions of a world war are derivatives of the United States, Russia, and an advanced moon-based society. Side effects of the war pushed the Earth out of orbit and the three civilizations are fighting for resources needed to build a spacecraft to escape the Earth and its moon.

Besides recalling images of Space 1999 and Silent Running, this umbrella goal serves two valuable purposes. First, it unifies the efforts of the individual missions and forces the player to consider resource conservation for the total campaign. Second, because time is limited before the Earth crashes into the sun, it drives a credible sense of urgency. When you fall behind the colony ship payment schedule, a computer throws reminders at you faster than an angry landlord. Earth 2150 thus inspires a scale grander than most RTS games and challenges the player with making decisions at tactical, strategic, and economic levels to address immediate and future needs.

Such scope comes at a price. The complexity of Earth 2150 is daunting, and isn't helped by the presence of poor documentation. The manual is a major flaw, doing little more than relaying the background story and brief unit descriptions. Missing are thorough explanations of the interface, details on the AI scripts, hard data on unit capabilities and upgrades, a needed in-depth tutorial, and strategic advice. Twisting the dagger in the consumer's back is the after-market strategy guide that contains data that should have been in the manual, and offers meager advice in the mission strategies.

As important as saving resources is, the balance between the long and short-term goals is intolerant to mistake. The strategic plans of the player are easily hamstrung by tactical decisions, and sometimes for the wrong reasons. It's too easy to fall behind in saving for the colony ship because too much money was spent on war (the liberals must be licking their chops at that concept). The lesson learned, that one should not be too prepared for war, is somewhat neutralized by the thought of learning the opposite and harsher lesson, that one was not prepared enough. Earth 2150 is too quick to penalize players that build strong defenses and armies to defeat the enemy in each mission. The art of practicing restraint in war is academically interesting, but tactically ludicrous, especially when the enemy comes at the player like gangbusters, and when victory objectives often specify enduring battles of attrition.