Good
The graphics were fairly detailed for a NES-style game. None of the backgrounds seem to have been reused. Different palettes during different parts of the story added to the effect of the scene while the backgrounds and sprites added to the feeling of playing a NES game.
The audio is good. The music sounds pony-esque and maintains the NES theme. Both audio and visuals manage to keep the theme of a pony NES game while remaining good quality.
The plot is good. When you enter the town where the blanks live, you hardly expect what is going to happen next, although the pony in the house with the crates foreshadows that something is terribly wrong. It could have been longer. It seems as though everything in the game happened quite fast.
The gameplay is good. The ghost ponies are enough to take most of the players off guard and keep them interested during the escape of the forest. More could have been done to add different gameplay elements. Most of the game is just talking to ponies.
You could contact Lauren Faust about turning the plot into a full movie or an episode.