- Main article: Standing Ground
Successfully survive the incoming waves of enemy Nod units. The challenge will be completed once all enemy waves have been defeated. If all GDI forces are destroyed you will fail the challenge. Reinforcements are available dependent on your performance.
- Main article: Infiltration
Eliminate all Nod presence in this large facility using the only combat unit available to you, the Railgun Commando. There are multiple sectors and each are more difficult than the last. If the Railgun Commando dies, you will fail the challenge.
- Main article: Outbreak
Defend your fortress from the incoming waves of Tiberium lifeforms. Enemy numbers increase over time and no reinforcements are available.