Added many signal / indicator lights for both usability and comedy reasons.
Removed many elements that were there only for the looks, potentially confusing the player.
Rearranged the first modules for better flow.

Usability improvements by a leap. Thanks TropiKo for the playtesting! It was invaluable.

Fixed a bug in the second teaching module. Thanks TropiKo for reporting!

Many small cosmetic changes. In particular, it should no longer be possible to accidentally lift off your lens cube with a light bridge and thereby undo the whole light bridge.

GLaDOS now detects if you trap yourself in a room near the beginning the test, and breaks you out from there if necessary.

Same purpose as previous update.

Cosmetic changes into the transport duct animation.

Just noticed that the accident a few versions back removed all the security cameras, too. So readded them, as well.

Aaand the antlines were missing again. For some unknown reason. Necessiting a dummy update.