Lots of great stuff in this thread.
Kaleth, I loved your version of the Moon Beach theme... but the BK3 character select music? DAMN! That's something else! I can't believe such awesomeness could come out of that trainwreck of a "song". Shame it's so short, though! You should definitely expand on it.
Expander is pretty cool too, but not crazy impressive like the other two, IMO. They all sound great though, and I can't really think of any criticism. Can't wait to hear more stuff from you.
Moe, I really like your mixes too, I'd definitely want to hear longer versions of the songs. Unfortunately the oldest stuff seems to have been removed, but here's a few comments on the songs I was able to take a listen to.
Construction Zone - Cool, I'm really digging the drums! They fit the song perfectly. I don't really like the rest of it as much... Actually, I'm not sure if it's the actual song/remix I dislike, or simply the mastering. The instruments sound nice, but the melodic parts are sort of faint in the background, and that just sounds kind of weird to me. If the melody was more prominent, and maybe the drums modified to make it sound a little more upbeat, I'd probabbly like it much more.
Beach - Well, it's certainly different from the original. It sounds kind of... I'm not entirely sure how to explain it, but it feels alot more calm, or soft compared to the original. It doesn't sound
bad, but I don't think it manages to give the same sensations as the original song. Of course, I don't know what your intentions were, but all things considered I do prefer the original.
Elevator - Awesome! I only have two quibbles with this one: I think the tempo should be upped a little bit, and I'm not entirely in love with the choice of lead instrument for the main part. Change those two things, though, and it'd be PERFECT.
Subway - Great! I really like this arrangement. The original version was a little chaotic, and some of those experimental, amelodic qualities which made some BK3 songs nigh unbearable... Yours is a little easier on the ears, and I like that. I really like the new drums, and the overall "feel" of the song. Somehow it feels a little more BK2, and a little less BK3. And that's a good thing.
Warehouse - Not really sure what to make of it. I wasn't a big fan of this song in the original game, and I'm not now either. The remix is faithful, but the subject matter is still uninteresting to me.
Mr. X - Hard to say what I think about it, to be honest. At this point I do think it sounds awkward, but it could just as well turn into something amazing once drums are in place. The drums/beat is what'll make or break this song, in my mind.
Yamato theme - Pretty cool, a little crazy sounding... definitely in the vein of the original song. It's a great start, but I think it's in dire need of a heavier, more clearly defined beat. With the right bass drum, I think it could sound really awesome.
Basketball court - Not bad, it's one of my favourite songs in BK3, and I think you're being faithful without being too boring. I'm not a huge fan of the intro, but once the song gets going it sounds great. It's hard to give a complete judgment as it sort of cuts off just as the song is about to "kick in", but it does sound promising.
Robot X - Well... the first version has awesome drums, and a great feel to it that simply gets you pumped to kick some ass, but the piano simply doesn't sound very good. The second version on the other hand, has a great sounding violin, and feels much more melodic... If you could couple the melody from the second version with the beat and tempo of the first version, it could sound really great. But as it stands I'm not particularly fond of either version.