Just go to https://weichensteller.online/ and wait for the game to load.
The rules are simple: Click on the switches to guide the trains to the right destinations (with matching colors). It starts slowly but gets faster and harder over time. Hurry up to set up the correct path!
There are settings to adapt the difficulty. If you play in a "placid mode", you collect points slower, though.
You can have your score saved online. Just enter your name and select your age. (There are differentt lists for different ages to give minors a chance to get to the front. Just be honest!)