Well, to begin with, that name is really fitting imo.
I'm also really impressed that this is an improvisation, although, I would say it shows. The melodies are amazing, but every now and then you can hear a brake that is slightly too long. Of course, those brakes can help with portraying the emotion, but sometimes I'd say they are a bit out of place. Nothing you can do about it since it's an improv. (Well, except run the midi file through a program and edit a bit, but maybe you did that already. Too much editing would take away part of the beauty of an improvisation though!).
That climax was just perfect! And that you managed to play it with such emotion is just astounding.
I don't dare complain any more than that; my own improvisations are rarely this good, and the very few that are are not recorded -.-
Thank you for recommending this, I really did enjoy it!
P.s. Was that pause after the climax (1:42-1:47) intentional or not? Anyhow, it really suits the mood :D