Command heavily-armed HERCs against relentless automated Cybrids (Cyborg Hybrids; intelligent creatures designed by mankind, who rebelled against us) in this MechWarrior-ish first-person simulation. Earthsiege is not a product of FASA's BattleTech universe (as the MechWarrior games are), though the resemblances are too close for legal comfort.
You control your HERC in 45 missions on varied terrain ranging from slaughter to escort to protection. Note that the game should ideally be controlled by more than just the keyboard for best play value. Full Motion Video clips from your commander detail your missions while keeping you in touch with the bigger picture as the war develops.
What you do outside the cockpit is also of great importance. Customize your units by choosing their weapons, and targetting research on the right new technology. Manage resources by collecting salvageable metals, and more to beat back the Cybrid invasion.