I found it; The start button is 's' # Press the start button during the first ball to add players.
# After the first ball, the start button starts a new game.
# Hold the start and the launch button to activate the attract mode again (useful to eject all balls from all locks before starting a new game).
# Hold a flipper button to see the status screens. The other flipper button switches between the screens. Switching through all the screens (and not pressing the second flipper button again) prevents the status screens from re-appearing. This is useful in the Europe exploration.
# Press escape to activate the menue. http://www.jeeens.de/t/t.html#parameter