Putas wrote:Is it supposed to be played in emulator?
No, it's port of the N64 game to the Doom data format used in modern, advanced engine ports of Doom (which are open source, so they can be made for Windows/Linux/Apple Mac/etc). You don't even need to download such an engine port (if you're a Windows user) as Brutal Doom 64 comes with one in the package. You do, however, need the official Doom2.wad file, which you can only legally get by buying Doom 2 (but who hasn't? I still have my original CDs of Doom 1 and 2!).
So just download Brutal Doom 64, unzip it to a folder on your PC, copy doom2.wad into it, and run the .exe to play!
You don't need a copy of the N64 version of Doom, or an N64 emulator or anything.