Here is the full list of all 12 Lara Croft and the Guardian of Light achievements worth 200 gamerscore.
Reflect an enemy's projectile back to him using Totec's shield
Kill 3 enemies with one bomb
Jump from Totec's shield while he is jumping
Activate all of the spikes at once in the Spider Tomb spike field
Vanquish the summoned beast in the watery depths
Regain the Mirror of Smoke
Collect all relics, artifacts and weapons
Catch Totec with the grapple while he is jumping over a death fall
Collect all 10 red skulls in any single level
Complete any level-specific Reward Challenge
Earn the top score objective in any level
Play Co-op mode