First enemy kill

You reached Paris.

You crashed Dierker's car.

You bested your opponents in the bar fight.

Finish all Campaigns on Standard Difficulty.

Collect one attachment of every type on a single character.

Eliminate 300 Pathogen.

Finish the "Giants in the Earth" Campaign.

Collect 25 attachments on a single character.

Equip three attachments on a single weapon.

Finish the "Priority One" Campaign.

Do a successful Challenge run.