You unlocked all the islands.

You completed the mission "Roman's Sorrow".

You unlocked the special ability of Roman's taxi.

You beat a friend at pool.

You have completed the first mission.

Finish the game in Crushing Mode

Kill three enemies with one explosion five times

Find 50 treasures

Kill 10 enemies with grenades by aiming while hanging from a ledge

Find 45 treasures

Reach max level with one class in the Cooperative campaign.

Complete single player Campaign on Superhuman.