Command and Conquer: Red Alert 3

Special units:
Successfully complete the indicated task to unlock the corresponding
special unit:

Crono Commando: Infiltrate an Allied Battle Lab.
Crono Ivan: Capture a Soviet Base, and build a Soviet Barracks.
Psi Commando: Infiltrate a Soviet Battle Lab.
Yuri Prime: Capture a Soviet Base, and build a Soviet Barracks.

 