While the bosses and levels are just taken from X1 and X2, I think this is just as good as the former, and way more fun than the letter.
The graphics, music, and game as a whole really is a damn fine conversion of the X games into 8-bit. It plays very nicely to boot, even in the X2 stages.
Easily tied with the original MMX as my favorite in the series (at least so far, haven't gone past X4).