I spent some hours with the game and posted some new hands-on impressions in Spanish:
http://www.revogamers.net/avances/donkey-kong-country-returns-impresiones-717/1.html
I guess most of you should know about the tidbits I stress in there, but just in case: there are 5 layers of animated backgrounds. Sometimes, they appear/popup super paper mario / another code R style. It's locked 60 fps. It has a genius part on the tsunami level where you have to decide whether jumping onto the crayfish, with the risk of being caught by the wave, or staying crouch, with the risk of that crayfish killing you :lol
I also loved the barrel-launching parts, the puzzles are awesome when I thought Rare had already came up with every idea with them. The destructible/changeable pirate ships are great, too. And all the Aztec-ruins type levels were incredible! I died like 894375 times, but I had a blast and I kind of got used to the shaking thing when in NES style.
So if you have any questions, shoot me a peanut