“Little obstacles with fun”
My six-year-old son, was the first tester. He did quite well. And played in the first attempt at level 20.
We had difficulties with the engineer blocks. Since we did not know when these were detected. But after an acclimatization phase everything went quite well.
Drag and drop program elements like turn left, right, go, … is not easy at times. But my son has not stopped playing the game.
He had the greatest fun as the alien has eaten the others.
The difficulty increases with time. As more and more features are unlocked.