This is the original classic, Super Mario Bros. 3 for the NES. It's a massive platforming adventure with an overworld map linking inventive levels. The visual style is vibrant and full of personality, making it absolutely worth playing.
The gameplay is tight and requires fast reflexes to master. A key surprise is the variety of power-ups, like the frog suit for swimming. With mini-games and secrets, it's a deep, rewarding challenge. You should definitely give it a go.