Your English is fine. I'm not a native speaker, so I know the struggle of getting stuff wrong :D
Yeah, the theme about society wanting us to conform to its standards was very clear and the horrors of having to force yourself to fit in came across perfectly with the graphic bits like the knives!
I didn't catch that Charlie knew it was a violent party and thus wanted us to stay away! I thought that Charlie simply wanted to make sure that we don't feel excluded/understand that we're great the way we are and I'm really glad you explained this :)
Little ideas like "a square which can't enter in the can" are what make great stories. They always start with silly little seeds like that and some of them just grow on their own :)
Our group pretty much only creates story focused games, so we also have a lot of ideas where we go "this is never going to be a proper story" and then suddenly it evolves all on its own.
Thanks for taking the time to write this answer and good luck with your future projects!