Not bad. . .
I really like the piece as a whole, the ending has a more baroque feeling to it or something excellent counterpoint!
As far as the first half have you tried giving the guitar some "grunge" I'm trying to hear it in my head, and I think it would be a good improvement.
As far as continuing the song or an ending I don't really have any suggestions. . .
I have a hard enough time to come up with those for my songs. . .
Omega