Here is the full list of all 40 Lara Croft and the Temple of Osiris achievements worth 1,000 gamerscore.
Complete all Lamplighter challenges
Complete all Silversmith challenges
Complete all Set challenges
Complete all Sobek challenges
Complete all Khepri challenges
Complete all Timekeeper challenges
Complete any level time challenge
Defeat Set
Complete the Tomb of the Architect
Defeat the Pharaoh
Complete the Tomb of the Torturer
Bomb a player in a Magic Shield in a local or online multiplayer game
Defeat Sobek
Defeat the Oracle of Osiris
Complete the Tomb of the Lamplighter
Complete the Tomb of the Ferryman
Revive another player in a local or online multiplayer game
Defeat Khepri
Collect enough canopic jars to unlock an onyx weapon
Get the most kills in a tomb in a local or online multiplayer game
Have the most deaths in a tomb in a local or online multiplayer game
Complete the Tomb of the Silversmith
Get the most gems in a tomb in a local or online multiplayer game
Complete any red skull challenge
Complete any gold score challenge
Finish any tomb in online multiplayer
Complete a Challenge Tomb
Complete the Tomb of the Timekeeper
Wear two rings and an amulet
Unlock a treasure chest
Escape the Pyramid of Osiris
Find your first weapon
Complete all Challenge Tombs
Complete all challenges
Complete all Pyramid of Osiris challenges
Complete all Ferryman challenges
Complete all Architect challenges
Complete all Torturer challenges
Finish a tomb in a 4-player local multiplayer game
In a 4-player local or online multiplayer game, be the only player to not die in a tomb