Yep it's midi, to be honest that doesn't bug me so much at all - it's a great way to practice with and I assume that when you've developed your songwriting skills enough, you're going to go find some adequate samples, so I will not bitch about that.
I like how this song strives to be somewhat rhapsodic, it works very well in some places. I'd advice you to work some more on recurring themes though. It can get a little all over the place to the point where I can't remember what the song was about in the first place.
For its samples, it's as groovy as it can get and there's some nicely controlled midi-action going on - tempo automation, dynamic variance etc - all nice stuff to experiment with.
Keep up the musical odyssey :) work on structuring your stuff and if you can get your hands on better samples, do so, but I'd rather hear a wonderful idea in midi than a crappy idea in shining VSTs.
Good luck and check out my stuff if you'd like!