Complete all training missions.
Complete a mission using cooperative play.
Complete every mission on the Medium difficulty.
Complete every mission on the Hard difficulty.
Complete every regular and bonus objective for every mission.
Unlock all one-player Bonus Missions.
Unlock all two-player Bonus Missions.
Unlock every ship.
Complete all Act I missions on any difficulty.
Complete all Act II missions on any difficulty.
Complete a mission without taking any damage.
Complete every hidden objective.
Complete every mission on the Easy difficulty.
