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.
Found all 179 Treasures
In one adventure, performed swan dives off the three highest points over water in the game
Performed swan dives off two of the three highest points over water in the game
Performed a swan dive off one of the three highest points over water in the game
Complete the game on hardest possible settings
Arctic Sea Expedition successfully completed
Found all 6 Relics
Andaman Sea Expedition successfully completed
Jan Mayen Island Expedition successfully completed
Beat all three Speed Demon challenges
Drove through the Valhalla Maze in under 40 seconds
Drove from the top of Valgrind to the bottom in under 50 seconds
Southern Mexico Expedition successfully completed
Found 100 Treasures
Drove into Xibalba in under 45 seconds
Killed five enemies by running over them with the motorcycle
Killed an enemy by running over it with the motorcycle
Croft manor Expedition successfully completed
Found 50 Treasures
Found 3 Relics
Coastal Thailand Expedition successfully completed
Killed three enemies with one grenade
Executed ten Adrenaline Attack headshots
Executed an Adrenaline Attack headshot on an enemy
Executed a chimney jump of at least 4 wall kicks
Mediterranean Sea Expedition successfully completed
Killed two enemies with one grenade
Found a Relic
Executed a chimney jump of at least 2 wall kicks
Found 10 Treasures
Prologue successfully completed
Complete the Beneath the Ashes Mission
Find the Hidden Relic and all Treasures in Beneath the Ashes
Find the Hidden Relic in Beneath the Ashes
Find all Treasures in Lara's Shadow
Find the Hidden Relic in Lara's Shadow
Find the Hidden Relic and all Treasures in Lara's Shadow
Complete the Lara's Shadow Mission
Complete a timed speed run from the first slope in the Refinery to the back platform without saving
After destroying the Transformer, beat a timed speed run through the unstable passage without saving
Complete the combat tutorial in Lara's Shadow