This is probably a weapon that was cut from the game during the development of DOOM 64. Midway had created a new weapon design that looked more like a flamethrower than a laser weapon design, that was seen in a magazine advertising their game, maybe Midway during the development of DOOM 64 they had the idea to create a flamethrower for the game but as the game developed they abandoned this idea of ​​a flamethrower for the game because maybe they thought it was not a good idea or it did not fit the game, or maybe it was a space limit issue in the N64 cartridge