ISO is a CD image.
in your cd burning program, find the "create CD from image"
if there are audio tracks with the game, burn the proper wavs as track 2-14 or so, but do make sure they are synced with the game. while most games don't have a 2 second gap at the ends of the song or vocal piece, Snatcher requires them, so that when people talk, it doesn't look like a badly dubbed godzilla movie.
to ensure a good burn, burn at 4x or slower, will take 15 minutes, but better than a coaster.