Thanks for that fast answer! I just updated my previous comment before I saw yours: vsync changes nothing if I force enable it in my graphic settings. Using Windows 10, up to date as well as GPU drivers.
Could you send the game log file to mail@playkids.ch? Maybe there's something hidden in there.
It should be here: C:\Users\<your_username>\AppData\LocalLow\Playables\Kids\Player.log