amrit9037: Now we only have Enhanced Edition with an in game option of "Original" version.
JMich: We do? I thought it was a different installer, so you could install either the Enhanced or the Original version. Are you sure you are not confusing it with different enhanced editions?
I think I remember hearing (maybe during a dev stream that I caught part of on Twitch.tv/GOGcom?) that there is an in-game options preset to play the EE with settings that will make it as much like the original as possible. This is, of course, in addition to getting the actual "classic" edition of the game in one's GOG library.
Not sure whether there was a similar option in the previous Enhanced Editions.