Walk: presenting it so it teaches itself

Both columns are playable. Each opens on a board that can't go wrong and adds one idea per board, with one line of guidance under it. No rules sheet before the first move. A square or dot you've cut off turns red at once, so you learn why a walk fails instead of finding out 10 steps later.

A. Squares, as now, taught by playing

The same game. Three boards teach one rule each (+, then ×, then numbers), then today's board 1. Red marks a square you can no longer reach.

B. Dots and lines (recommended)

The board draws every step you can take as a line. "Visit every dot once, along the lines." Nothing to work out from symbols: you see the moves, and the puzzle is the route. No numbers needed; every board still has exactly one walk.

Why B

In A you read a + or ×, then picture where it leads, several steps ahead. That simulating is the hard part, and it isn't the fun part.
In B the moves are on the board. The thinking that's left is the good kind: "this dot has only two lines, so the walk must use both". The game teaches that on its second board.
It reads at a glance on a phone at 8 by 8, and it's the same game underneath: a walk through every square, one step at a time.

Staging