Snake

Classic snake is single-player against the walls and your own tail. Snake.io puts you in an arena with other players, so the main danger becomes someone else cutting across your path deliberately.

By making other players run into you rather than by outgrowing them. Cutting in front of a larger snake is the standard move, and it's why the biggest snake in an arena is often the most vulnerable one.

Snake crossed with number merging. Snake 2048 has you collecting numbered blocks that combine as they match, so growth is about building a value rather than simply getting longer.

Ideal, really. A round lasts as long as you survive and there is nothing to save or come back to, so they suit a five-minute gap better than almost anything else on the site.

Yes. They were born on phones and the controls are simply a direction, so swiping or dragging works as well as arrow keys do on a desktop.