About a year and a half again, I purchased this wonderful game "Machinarium" from Amanita Design at the Ubuntu Software Center. Now, after I got a new Laptop Computer, I wanted to re-install my previously purchased game. However, it is not available anymore in the Software Center. I contacted Canonical Customer Service about this. No answer. I wrote to Amanita Design as well. No answer!
The answer to the marked duplicate question was: "In the Ubuntu Software-Center, go to File > Reinstall previous purchases but this did not work for me.
What can I do?