School

Mostly escape and stealth games that use a school building as the environment, plus one where you're on the teaching side instead. The setting supplies the layout rather than any particular mechanic.

Escape from School 3D. The objective is clear from the first screen and the layout teaches you how these games expect you to move through a building.

Escape School Duel turns the escape into a contest rather than a solo puzzle, which changes the pace considerably and gives you someone to lose to.

High School Teacher Games Life puts you on the other side of the desk, which is an unusual perspective for this tag and worth a look for that alone.

Yes, all of them run free in your browser with nothing to install and no account needed before you start, whichever side of the classroom you end up on.