Reloading the demo a bunch of times, there appear to only be a handful of different games. Maybe they have a reduced set for the demo, but it certainly seems like each game would require human intervention to create. They don't look that difficult to solve automatically once a human teaches the computer what to do for the given game once. CAPTCHA relies on being able to create new puzzles with zero human effort but which require some human effort to solve. If each puzzle requires human effort to create, then attackers can simply take advantage of the fact that their time is cheaper than yours.

These sort of clever/unusual human detectors can work great on a small scale, when it isn't worth anyone's time to attack them, but fall apart once they get popular. Maybe I'm missing some secret sauce here, but this one certainly looks like one of those.