Full list of all 50 Just Cause achievements worth 1,000 gamerscore. It takes around 25-30 hours to unlock all of the achievements on Xbox 360.
Liberated Every Province In San Esperito
Completed Every Race Mission
Completed Race 1
Completed Race 7
Completed 50 Side Missions
Completed 40 Side Missions
Completed 30 Side Missions
Liberated 22 Provinces In San Esperito
Liberated 11 Provinces In San Esperito
Completed Race 2
Completed Race 9
Completed 20 Side Missions
Completed All Stunts
Completed 20 Air Vehicle Stunts
Completed 20 Land Vehicle Stunts
Completed 20 Sea Vehicle Stunts
Completed All Story Missions
Completed Race 4
Completed Story Mission 14
Completed Race 3
Completed Race 6
Completed 45 Takeover Missions
Base Jumped From 1000 Meters Or Higher
Completed 30 Takeover Missions
Completed Story Mission 7
Completed Every Collect Mission
Completed Collect Mission 3
Completed Collect Mission 10
Completed Collect Mission 11
Completed Collect Mission 5
Completed Collect Mission 6
Completed Collect Mission 4
Completed Race 5
Completed 15 Takeover Missions
Killed 500 Enemies
Completed Collect Mission 9
Completed Collect Mission 13
Survived For 5 Minutes With Maximum Wanted Level
Survived For 2 Minutes With Maximum Wanted Level
Survived For 1 Minute With Maximum Wanted Level
Completed Race 8
Completed Collect Mission 7
Completed 20 Car-To-Car Jumps
Completed Collect Mission 12
Completed Collect Mission 8
Killed 250 Enemies
Completed Collect Mission 1
Completed 10 Side Missions
Completed Collect Mission 2
Killed 100 Enemies