I love piano,
And what you did here, sir, is brilliant. When the guitar and drums kicked in that brought the song to a whole new level. This is really good. Perhaps a bit too simplistic for my tastes (but maybe that's because there's no vocals). Everything about this piece is written perfectly, it's way too often I catch off-key note after off-key note is some peoples music... and that just sends my ears screaming for the hills. The only off key note I noticed in this song was at 2:27. Whatever that note is, it just isn't working, haha.
I strongly suggest getting some vocals for this, if you ever do contact me so I can DL and fav the song!
Cheers!
PS: I love the outro to this song as well. Great job man.