hey, thanks to all you! about the checkpoint thing: i didn't want to add something like that, because the game is pretty short and i fear the challenge would have been gone with CP in it. it's not that hard, just concentrate for a few minutes ;)
about the story and the ending: "closed in" is a nightmare that's coming again and again to the main character. the drop you are falling down at the end is the same you see at the start. BUT: there is hope... i'm wrapping my mind about an addendum to the game at the moment!