It was a tile-by-tile remake. The only maps that are 100% mine are the "Cave of Trials", where the Abomination is. You can rip on me as much as you want on that front.
The only map that underwent any revision was the Lava Cave. I suppose I could have made some code to allow for terrain damage for going over the lava (as per the original version of the game). Depends how many people scream foul now that I said that...