The expansion pack added several new campaigns and features to the game, but there were many small bugs that were never addressed by Mad Doc Software.

The game also included 21 nations, from every age and location. The game had 14 epochs in it, which totaled 500,000 years. The 2 million unit sales were enough to spawn an expansion pack and several sequels to the game. The game was praised for its in-depth gameplay, and received positive critical acclaim. It was developed by Stainless Steel Studios, and published by Sierra Entertainment. The games use the Titan and Titan 2.0 engine, which was sold after Stainless Steel Studios closed. Rick Goodman, who designed Empire Earth and Empires: Dawn of the Modern World, was one of the lead designers of Age of Empires. The games in the series are historical RTS games that are similar to Age of Empires. The Empire Earth series is a franchise of real-time strategy computer games developed by Stainless Steel Studios and Mad Doc Software, and published by Sierra Entertainment, Activision, and Vivendi.