Update: Finished the Labyrinthmaschine

So, I finally got the right size of cardboard and some free time to finish up the Labyrinthmaschine with side panels. This means the user interface part of the cardboard arcade cabinet is not facing upwards in a 45 degree angle which is much, much more comfortable to play than before. I played the game a few times since the upgrade and the pinball machine has seen some use as well recently (by both me and my older son who can't slam the trigger hard enough to get the marble over the bridge but still enjoys it). Current record for speedrunning the Labyrinthmaschine was 1 minute and 52 seconds. The one recorded for a player other than me is over four minutes. This is the final version: