Very cool medley! I've got to say that some of them blended in well together (Steampunk Suspense & The Dragon Chef's Belly), while some changes were a little abrupt, but you'll get that in medleys. The scorings themselves were very well done; I recognised almost every note from the original tracks.
The Betilla track sounds quite accurate too, but like Adsol said, you might want to look into the overall production of your tracks (equalization, balancing, velocity, etc.). Somehow your sounds from KONTAKT sound very soft when you use them, almost like everyone is stroking their instruments. I guess you're not using a MIDI keyboard to play in the notes, but rather your mouse and regular keyboard? I highly suggest trying some kind of MIDI device, because you'll get a much more natural feel if the first recordings already have some kind of velocity difference in them, which you can then later adjust according to own preference, of course.
Now comes the tricky one! The main theme for Rayman 2 is one of my favourite pieces of music of all time. I know it note by note, instrument by instrument. Let's see how it compares.
Wow! I heard almost every piece of instrumentation that I love so much. The only thing I really missed was some of that robotic 'oomph-oomph' sound you should hear in the Pirate Ship part of the theme (2:04 and onwards). But, regrettably, again, the music lacks power. It could be so much more impressive if only it had some more dynamics. It simply lacks 'fullness', if you will. That doesn't mean you should turn it into a wall of sound, oh no! But listening to the Rayman 2 track carefully (which I'm sure you've done excessively already, given how accurate your work is) will tell you more than I can in words.
But as it is - as all tracks are: astounding work! You have a good ear for notes; now get a better ear for music!