This achievement will unlock once you have completed the 3 stages of the 'Temples' level and defeated the boss Olmec. You can use the shortcut to start at the Temples and this achievement will still unlock.
If you are having trouble clearing the Temple, read these tips:
Mummies: If one is coming towards you and you have no other way around it, you can place a bomb in front of it so it falls through. You can use its head as a platform.
Anubis: Their attacks can go through terrain and will kill you in one hit. Avoiding them entirely is smart, but it is possible to kill them with weapons. That will take some effort though. You can try to get them in front of a tiki trap, which will kill them.
Olmec: For the fight against Olmec you will want some ropes and/or climbing gloves. A jetpack will help too This is because you need to get him to fall into the lava below the stage and you'll have to get down low for him to die. He will smash the ground when you are underneath him, so one popular strategy is to go underneath him, then quickly run just a block out of his way. Then run back under and out 1 block each time he comes up. You repeat this process until he's got one block between him and lava. Get ropes sent up or be ready to jump to the wall if you have climbing gloves. Now carefully make your way to the exit on the right side of the stage, avoiding the few enemies as you go.
Crush Trap: If you dodge it, don't think you're in the clear quite yet. You are most likely in a position where it will still come after you, so make sure you aren't straight across from any side of it.
See Ice Creamed for information on the Temple shortcut.