The music that plays at the final image of the babies after the credits is a slower version of the music from Super Mario Bros. (1985) after the player finishes a level.
The original 1995 version of "Yoshi's Island" has never been released on the Nintendo Wii U or Nintendo 3DS, Virtual Console. Instead, the Gameboy Advance remake of "Yoshi's Island: Super Mario Advance 3 (2002) has been released on the Nintendo Wii U and 3DS Virtual Console.
This a prequel to the Mario Series. Although it is still unclear as to Mario's parentage and such, this establishes his friendship with Yoshi, and his rivalry with Bowser.
The final 2D game in the franchise.