I cannot provide a direct download link. "Super Mario" is intellectual property owned by Nintendo. Downloading unofficial fan games or ROMs from random websites carries significant risks:
To help you get started, here's a brief tutorial on creating a simple Mario-style game: Super Mario Unistudio Download
Unlike bloated modern games, Super Mario Unistudio runs on almost any Windows PC from the last 15 years. The file is only ~200 MB. I cannot provide a direct download link