Thank you very much!
Took a while to find the "Id" in the properties but it works now. :)
+ Touch: On hold gesture over CustomButton
-> Timeline: Set CustomButton to track "AnimButton" of the next timeline
-> Timeline: Play SetDefaultGame with tags "AnimButton"
-> System: Wait for previous actions to complete
-> CustomButton: Set size to (506, 87)
-> CustomButton: Set opacity to 100