I played this game when it first came out, and I still play it to this day. It's that good.
Some gamers may turned off by the slow paced turn based gameplay, but if you give the game even a little bit of a chance you will be enchanted by it.
3DO unfortunately has shut down, and the Heroes series is now in Ubisoft's hands. They did an alright job with HOMM V, but it basically stole most of the gameplay with this game and plastered it with newer graphics. HOMM V lacks the charm and beauty of this game. HOMM III's graphics are outdated and show their age today, but it is an undeniably amazing game.
This is easily one of the games I have spent countless hours on, and I do not regret any of it.