Before starting, I recommend taking a moment to equip items that increase speed. In addition to simply getting through the tricky run without dying repeatedly, there's a Challenge: Step on All Ammit Crumbling Floor Tiles in Exit. There are 8 tiles with Ammit's image in all. The following screenshots show them all.

When you're ready to go, Begin by lighting any of the gas vents with your torch.

This sets off a chain reaction that opens the gate ahead and triggers a series of floor spikes. The white circles indicate where the spikes will pop up, so get going. Run forward across the collapsing tiles, jumping over the gaps where there are missing tiles. Stay to the right at first...

...since the first Ammit tile is just ahead on the right.

Then work your way across to the left as you move forward.

The second Ammit tile is on the left...

...and the third tile is in the middle.

After the first section of collapsing tiles there's a solid ledge with a couple of Sobek's minions standing on it. This also serves as a checkpoint. So if you're going after the Ammit tile challenge and miss one, you can reload before you reach this checkpoint and try again.

Don't linger on the ledge with the enemies, since spikes pop out of the floor after a few seconds. Jump onto the next set of break-away tiles...

...then continue forward and left to reach the fourth Ammit tile.

Now the entire walkway takes a turn to the left. Keep going straight ahead as you aim for the right side of the walkway beyond the corner. Here you'll find a pillar with a nice cache of gems on it. Grab them if you can. If not, don't worry; just try to stay along the right side as you round the corner...

...since the fifth Ammit tile lies along the right edge.

[Part 2 | Return to the Tomb of the Lamplighter Walkthrough]