Super Boy 3

Super Boy 3
Developer: Zemina Publisher: Zemina Platforms: MSX, Unlicensed Sega Master System Released in KR: 1991 This game has unused graphics. This game has a Data Crystal page

Super Boy 3 is the third installment of Zemina's Super Boy series, primarily based on Super Mario World but also having some elements from Super Mario Bros. 3.

It's also the first installment in which the titular hero actually gets to rescue someone.

Unused Graphics

Starting at 0xD740 in the ROM is graphical data for Morton Koopa and Ludwig von Koopa, based on their sprites from SMB3. It's likely that they are scrapped bosses, given that their sprites are directly after the Sledge Bro's.

(Source: tikal.)