It is one short journey, not a level-based platformer
Road to School is built as six scenes played straight through: a title screen, a controls page, the living room, the town, the road crossing, and the classroom. There are no levels to select, no score, and nothing to unlock. The developer's own description calls it a short game about a kid's journey to school, and that is an accurate summary. You can reach the ending in a single sitting without much trouble.
That structure is worth knowing before you start, because it sets the right expectation. This is closer to a small illustrated story you walk through than an arcade game you grind at. Most of the runtime is spent moving right and reading text, and the game is perfectly happy for you to take your time doing it.