I enjoyed it. I like how a lot of it flows into new passages based on what came before.
my favorite passages and comments:
3:29 - I like the left hand here, it sounds independent from the right hand in many spots.
4:14- I like tremolo figures like this
5:18- Cool left hand melody here in octaves
6:09- really nice harmony changes, I like surprises like that
6:32- creepy clockwork passage (by clockwork I mean steady beats)
8:17- cool mode change or chromaticism.
10-15- nice little rhythmic thing.
11:07- cool stairstepping octaves.
11:52- nice arpeggios and harmony changes here
12:something- you bring back that figure you played before, thats cool...
12:40- creepy
14:00-another cool rhythmic thingie
14:15-nice arpeggios and melody rising out of it
14:55-I like this melody here
16:50-I like the harmony change here and semitone dissonances
I think you're doing very well. You should keep it up! Not knowing what you're doing, and being comfortable with not knowing what you're doing (on a logical, conscious level that can be verbalized, anyway) is important for being able to improvise fluently. That is true at least with spontaneous improvisation. Anyway great work and i've added your name and your improvisation to the "Index of Improvisers and Improvisations List"

Hope you post more!