There are 12 Trophies that can be collected.

Bronze

Environmental Exterminator
Destroy a Spider using spikes (General).

That's Teamwork
Destroy an enemy using a Kamikazer (General).

Don't Go Alone.
Complete any Co-op Challenge Room (General).

Enthusiast
Collect 10 Marks of the God (Single Player only).

Two Birds
Smack a bomb so that kills two or more enemies (Individual).

Survivor
Kill 20 enemies in a row with only 1 health left (Individual).

Overkill
Destroy six enemies with one Beam Shot (Individual).

Silver

Arcade Master
Complete any Arcade Chapter below the target time.

Untouchable
Defeat any boss without taking damage (General).

Collector
Collect all Marks of the Gods (Single Player only).

Millionaire
Collect 1 000 000 Doubloons (Single Player only).

Gold

Grand Master
Complete full game (Individual).

http://www.ps3trophies.com/forums/trophy-news/61956-outland-trophy-list.html