What it teaches
Planning a sequence and then testing it. Block-based programming has a documented effect on problem solving at this age, and the effect comes from the order: the child commits to the whole plan first and only then sees it run.
From the second maze the robot must collect batteries before the star counts. They sit off the direct route on purpose, so the order they are fetched in changes how long the program is. That is a real planning decision.
How it works
A maze is built fresh every time — six sizes, from four by three up to six by six — so the game cannot become a memory test. The screen says how few steps the maze can be done in, and that number is worked out rather than guessed.
When the robot hits a wall it stops, and the arrow that caused it keeps a red cross after the robot returns to the start. The cells it walked through stay lit. Both are there to answer "what went wrong?" rather than to say "wrong".
What to look for
Ask the child to say the plan out loud before pressing Run. Reading a program back is the habit that finds the mistake, and it is worth more than any hint the game gives.
A shorter program earns more. A child who notices that is doing optimisation.