Rimuru Tempest in SMB1 is a hack of Super Mario Bros replacing Mario with Rimuru Tempest from the manga "Tensei Shitara Suraimu Datta Ken" ;)
Rimuru is faster, jumps higher and throws fireballs differently compared to Mario
Yuri's character sprites (drawn by Valis Emma) were used as a base to make Rimuru
Database match: Super Mario Bros. (World)
Database: No-Intro: Nintendo Entertainment System (v. 20210216-231042)
File SHA-1: EA343F4E445A9050D4B4FBAC2C77D0693B1D0922
File CRC32: 3337EC46
ROM SHA-1: FACEE9C577A5262DBE33AC4930BB0B58C8C037F7
ROM CRC32: D445F698