Lovely game, very well written. I got Will good ending and I enjoyed it so much that I am reluctant to read another route XD
I like all the backround and explanations about what it is to be a gost (the obsession, the emotions that can be dangerous, etc.)
However, I am French and I couldn't help but notice some mistakes in the sentences pronounced by Sister Agnes:
*"Ouvre la porte! Je sais que tu EST dedans!": the verb is mispelled ("est" is for the third person singular. The second person should be "es"), and the last word is a bit akward. It would be correct to write it like this instead: "Ouvre la porte! Je sais que tu es à l'intérieur!"
*"Mais qu'est-ce qui se passe les enfants? Pourquoi criez-vous?": "crier" in french doesn't mean "to cry", but "to shout". To cry="pleurer". So, the correct sentence would be "Pourquoi pleurez-vous?".
Sorry to point out these errors, but when you are french, those are quite immersion breaking. But I know how it is difficult to write in a foreign langage, my english is very akward^^
Apart from this, congratulation, this was a very pleasant story.