Full list of all 41 Tomb Raider: Underworld achievements worth 1,250 gamerscore.
The base game contains 31 achievements worth 1,000 Gamerscore, and there are 2 DLC packs containing 10 achievements worth 250 Gamerscore.
Prologue successfully completed
Mediterranean Sea Expedition successfully completed
Found 10 Treasures
Performed a swan dive off one of the three highest points over water in the game
Executed a chimney jump of at least 2 wall kicks
Executed a chimney jump of at least 4 wall kicks
Found a Relic
Performed swan dives off two of the three highest points over water in the game
In one adventure, performed swan dives off the three highest points over water in the game
Killed two enemies with one grenade
Killed three enemies with one grenade
Executed an Adrenaline Attack headshot on an enemy
Found 50 Treasures
Found 3 Relics
Killed an enemy by running over it with the motorcycle
Executed ten Adrenaline Attack headshots
Coastal Thailand Expedition successfully completed
Croft manor Expedition successfully completed
Found 100 Treasures
Drove into Xibalba in under 45 seconds
Drove from the top of Valgrind to the bottom in under 50 seconds
Drove through the Valhalla Maze in under 40 seconds
Killed five enemies by running over them with the motorcycle
Southern Mexico Expedition successfully completed
Complete the game on hardest possible settings
Found all 179 Treasures
Found all 6 Relics
Beat all three Speed Demon challenges
Jan Mayen Island Expedition successfully completed
Andaman Sea Expedition successfully completed
Arctic Sea Expedition successfully completed
Beneath the Ashes Mission successfully completed
Hidden Relic and all Treasures in Beneath the Ashes Found
Hidden Relic in Beneath the Ashes Found
Hidden Relic in Lara's Shadow found
Completed a timed speed run from the first slope in the Refinery to the back platform
After destroying the Transformer, beaten a timed speed run through the unstable passage
Completed the combat tutorial in Lara's Shadow
All Treasures in Lara's Shadow found
Hidden Relic and all Treasures in Lara's Shadow found
Lara's Shadow Mission successfully completed