Gotta be a real cool dude to remix DKC2's mineshaft theme. I'll take a look.
Piano seems a bit loud and dry; I'd drop the volume a bit and add a delay.
Actually, everything seems too dry. Don't drench it in effects, but a touch of delay and/or reverb on a few of the synths could help a lot.
The whole mix seems a bit treble-heavy. Back off a bit on the higher frequencies.
Noticeable clipping on the pianos.
I'm digging the percussion in the slower section, though it's a bit loud. Could afford to be spiced up a bit, but I like the samples. That snare has some real character.
Biggest issue is definitely mastering; the whole thing is too loud and too treble-heavy. Second biggest issue is that the leads are too dry. Percussion could be brought down a bit, and could really use some more variation. Play around with velocities on it.