hmmm
I can't really tell if you've just messed up a midi of the theme, or played it on a keyboard, or what, but anyway, you really need to flesh it out. A lot. At least add drums. Also, I'm no Jazz expert but you don't need to play superflous little bits for no reasons. Usually with thing like this, you're better off sticking pretty closely to the original song. I did a remix of tetris too, but more orchesteral, and it turned out a lot better because I let the original piece of music show.
Still, good effort though. Good luck with your future stuff!