After some fixing and changing, I have released a newer version of the demo to the Portal 2 Workshop. Click here to add "The First Slice" to your subscriptions.
Please leave feedback here or under the maps in the Workshop. Playtesters are the most important part in the progress towards releasing a perfect and fun experience.
I have also uploaded 2 new screenshots of Chamber 18. After a long break (Arm injury), I have continued and am motivated as always.