Unmechanical: Extended

There's a room with one laser beam and four mirrors.
The pentagram is not a perfect star (as in the achievement artwork), so don't try to make one.
Rotate the mirrors by using your tractor beam on the red orb nearest it. There are also three mirrors below the water line, and you will need to use these (and also for the solution to escape the room).
You will want the lower-right mirror to remain flat. With the lower-left mirror, angle the beam onto the second-from-right mirror below the water. That will bounce the beam up to the top-right mirror. Using that one, angle the beam onto the left-most mirror below the water, which bounces the beam onto the lower-right mirror.
This completes your pentagram, but you must go down and admire your complete work for the achievement to pop.
Bonus: solution for escaping the room:


This video from "aka Scratch" demonstrates this achievement.

In the second part of the game you will come to a room with mirrors and lasers. Angle two mirrors like in the video so it makes a pentagram.

In the first laser and mirrors puzzle in Chapter 2, you need to position the mirrors to make a star. Some folks say it's a pentagram, but I don't think it really qualifies as one considering it's lopsided as all heck and isn't in a circle, lol. Check timestamp 0:11:58 in the walkthrough video for this one.

Shown in Video at 3:04

You will come to a section with a lasers and some mirrors you can rotate (some mirrors are in the water). You will have to form a pentagram out of the light reflections from the lasers of the mirrors.

1) Rotate the bottom left mirror 5 times
2) Rotate the top Right mirror 9 times