In this SMB1 hack, based on the look of the Virtual Boy, everything is red.
This hack is 1 world long and has 5 levels.
Super Mario Bros. (World).nes
CRC32: 3337EC46
MD5: 811B027EAF99C2DEF7B933C5208636DE
SHA-1: EA343F4E445A9050D4B4FBAC2C77D0693B1D0922