Sleepwalker wrote:
Is the last area not finished yet, because it only served up one ball for me even though there was three loaded.

It's supposed to work like that. You have to use the first ball to release the other two in turn, using the mechanism below the tray where the balls are.

Sleepwalker wrote:
Btw, you can still cheat in the first room if you're fast enough and you place a portal above the doorway.

I don't know exactly how that would work, but i'll try it. Thanks for the tip!

Aof wrote:
About getting stuck in the "glass pipe" thing in the last level -
I didn't even have to use a portal near it. I simply walked up to it and got stuck inside it.

This calls for a few clip brushes. Thanks for the tip!