Voxels

While Outcast was being developed, 3D game engines based on polygons were becoming popular for designing games in three dimensions. Appeal, however, used an engine based on voxels; they wanted to design more organic landscapes.

Artificial Intelligence

The most cutting edge piece of technology Appeal created was the artificial intelligence engine: GAIA. GAIA made it possible for the artificial inhabitants of Adelpha to have their own daily routine, and to react to the behaviour of the player and their environment.