Whoah, this is quite impressive!
This is really so good it could easily have been a commercial indie release, I love the graphics and the music is good too.
And also - it really plays like the original as far as I can tell, I've played that one a fair bit.
A bit hooked on it at the moment, decided I'll try mapping it all out this time... I used to always get lost when playing the original, was too lazy to map it