I am pleasantly surprised. Normally, when I see something like this, I end up with a heaping mass of poor decisions pasted together that could barely even be called a game, named weirdly, and claims to be a "fan" project related to a franchise, only to actually be an insult to that franchise.
This, on the other hand, was absolutely great. I only have 2 issues with it, and neither are bugs (I didn't even notice a single bug, so great work there!):
1) One of the most instrumental parts of the original, a move that Quintet deemed so necessary that they put it in all 3 of Soul Blazer, Illusion of Gaia/Time, and Terranigma, is sadly absent from this - the psychic pull, which in this game is also known as the "crab walk" due to you holding your sword in a ready position and strafing. There were a couple of minor reasons to use this, but the main use for it in this specific game, was to pull jewels to you from a distance, so you wouldn't have to put yourself in harms way to pick them up. It was also useful to tell when an enemy was in your range (and outright dealing with weaker ones), but the game wasn't really long enough for that to be an issue.
2) It's too short. Perhaps that was the point, but I really felt like you could have done more with this. You had just about everything down, that the game uses, you probably could have literally made a full on remake of the original... though I don't blame you for not doing that, given who owns the rights to this game now. Maybe an extra boss fight or something would have helped, but while this game was good, it stopped right at the point where I wanted more... and there is none aside from replaying the original!
Thank you for actually caring enough to make your fan game actually feel like the original, and uploading it so that the rest of us could see it. It was a pleasure to see something that, for a change, was not an insult to the franchise it's a fan game of.