Y Dream Theater is hard.
I tried learning As I Am for guitar. It went... kind of good, but the solo was impossible. My brain died by reading the tab and trying to play it, so I'd improvised during the solo parts.
I also bought this
and tried learning my favorite dream theater songs. But first of, it was only the keyboard parts, not fully arranged piano arrangements
. And secondly it was hell of hard.
But I think that a lot of Dream Theater songs could sound good on piano. And some might not be so difficult like This is the Life
, one song I had in mind.