Needs a little more work on the code. The battles are too fast and after my second battle with a red slime the game movement controls froze. I was stuck on the hills. You also have the mountains as passable. you can slip in between the tiles and walk over the mountains above Brecconary. Seems to be an issue with hills. I can wiggle from the hills to the mountains. The menu is missing the status and it auto hides sometimes. almost interesting but the battles really drag it down. hit attack and battle over. no animation for the action, no text for the damage, the enemy sometimes attacks before the screen is even displayed. level up is just a block of text.
It's certainly an similar version but not that close to be considered a true 3d of the original. (nes version from my experience)
Good effort, keep trying. I'm finding some difficulties as well trying to remake this same game in rpg maker vx ace. Everything can't be exact.
Also I thought the magic key in the throne room was in the chest behind the walls. Maybe you should make the chests disappear after getting them.
You do not have the stairs command so this will force you to adjust some maps.