Level 13: Six Thousand Feet Under
As long as this level is, there are a few tricks to make the most of it. The key is to get as high up as possible.

While making your way up you will notice at one point a save terminal, apparently in a strange place. However, you can jump down to it.

Once down at the save terminal there's apparently no way out. Behind you there's a switch which will raise a platform near another terminal - use it!

After reading the terminal and hitting the second switch you can get back through this way. Before the switches were activated this was just a pool of lava.

On your way up there's a room full of lava that may be explored. To lower the lava first find this location.

To aid you, here's a map detailing the path to take. Instead of following the stairs up jump down to the path below.

This path leads to a small room with a switch and a terminal.

After the previous switch is activated the lava in this room drains away. Jump across and check out the rooms beyond.

After hitting the previous switch continue upwards. Apparently the path ends abruptly. However, if you look carefully you can jump across at this point.

Once across continue a few steps to the right. Look down and you can see a platform way off in the distance. You have to jump down to that platform.

After landing on the platform and making your way through the rooms beyond, find a path that once again leads upwards. At the end of these new steps there's a small room with several switches. One of these switches will raise a platform containing the exit terminal.