Downloading copyrighted commercial ROMs (even for old games) is legally gray-to-illegal in most regions. Fan hacks typically require you to own and dump your own copy of the base game.
It sounds like you’re referring to a long-running rumor or a fan project. To clarify for anyone who might be searching for it: Donkey Kong Country 4 Snes Rom
The original trilogy ( DKC1 , DKC2 , DKC3 ) was developed by Rare and released on the SNES in the mid-1990s. A fourth mainline entry didn’t appear until Donkey Kong Country Returns (2010) on the Wii, and later Donkey Kong Country: Tropical Freeze (2014) on Wii U/Switch. Downloading copyrighted commercial ROMs (even for old games)