Console Monster writes: "We have just added the Achievements for Tomb Raider: Underworld on the Xbox 360. The achievements confirm the game will feature collectible 'treasures' and 'relics'. It also confirms the ability to swan dive, wall kick and drive motorcycles. There are seven secret achievements worth a total 475 GamerScore. The secret achievements could be related to the story mode due to the lack of mentioning of the story mode in the already-known achievements.
The list contains 31 achievements worth 1000 GamerScore:
Prologue - 25 GamerScore
Complete the Prologue
Master Survivalist - 100 GamerScore
Complete the game on hardest possible settings
Treasure Collector - 30 GamerScore
Find 10 Treasures..."