Super Mario Flash is a fan-made browser platformer built in the classic Mario mould: run right, jump on enemies, hit blocks from below, and reach the flagpole at the end.
It's a tribute rather than an official game, and its lasting appeal was the level editor culture that grew around it — players built and shared their own courses for years.
No — it's a fan-made Flash tribute built in the classic style. Nintendo's Mario games are separate commercial releases.
No — this version runs in a modern browser with nothing to install.
Yes — a light 2D game with nothing to install.