This idea is to create a 3D real-time multiplayer strategy game (like SC2 — Starcraft II) played exclusively underground, it could have the following features :

• Underground foundries for refining underground resources.

• Beacon to uncover the fog with electronic resonance (here the rock).

• Different type of diggers (size, speed, etc.). 

• Underground assault units with diggers.

• Underground vehicles.

The game could be to capture the flag or to dominate the adversary and map. A little revolution could be a gameplay taking place on two or more underground layers : meaning you can switch layer and make attacks the adversary on the layer 1 through the layer 2 and conversely. If there's 3 layers the second being *the* place.