Snail Bob 2 is a point-and-click puzzle series staple: Bob walks forward relentlessly and cannot be steered, so your only control is the environment — levers, platforms, buttons and switches you click to change what's in front of him.
That constraint is the whole design. You can stop Bob and you can change the world, but you cannot make him do anything, which turns each level into a timing-and-sequence problem.
No — only stop and start him. Everything else is done by changing the environment, which is what makes each level a sequencing puzzle.
Yes — it's a gentle puzzle game with no violence, and it's a popular one in classrooms.
Yes — a light 2D game with nothing to install.