I rented the game and spent about 10 hours that day going through all 8 worlds but had to divert the final boss for the next day. I had the same stale nostalgia problem for the first 4 worlds or so but now that I've beat the game and am revisiting old levels for KONGs and puzzle pieces I finally notice a lot of the small details I had ignored and am actually enjoying the earlier stages much more the second time around. Rushing is never good. The latter worlds get pretty cool, like the factory. The silhouette levels are also neat and the -k temple levels are challengingly fun. I still need to get all the orbs to see the final stage.
I use to play DKC on my SNES and have from time to time fired up an emulator for DKC2. Even with a million save states, DKC2 is devilish. DKCR is far more forgiving and the controls and physics/collision detection make it feel so much smoother and controllable than the older games. It's a big step forward, with no invisible walls and weird sudden deaths or dropoffs. The ground feels real solid, if that makes any sense. I get high from doing 1-K Platform Panic since I feel like a real pro on a speedrun and I can pull it off without stopping, even though I'm not that good and it's really just the level design.
The shake controls, however, are annoying and really deter from the fluidity. Trying to keep one finger pushing the down button, another on the 1 button, and shaking the too-small-and-not-designed-for-horizontal-use-but-shoehorned-in-for-legacy-purposes controller to blow on enemies quick enough is disorienting. Another big issue is when bouncing off enemy heads. The high bounce doesn't always trigger and is especially frustrating on this later temple level where I have a hard time bouncing on this one particular enemy and end up dying a hundred times.
Like others have said, the bonus levels are disappointingly bland, and I miss collecting super gigantic coins to pay toll fees. The puzzle pieces are poor substitutes and remind me too much of Braid. The lack of more furry (or fishy) friends is noted. And whatever happened to the water levels?
The older DKC games had really nice CGI sprites and levels that were on the more realistic side. The atmosphere was also darker, more ominous, and the music stronger and more emotional. DKCR kind of puts a different spin with the Wii's sometimes annoying family-friendly approach. The graphics are more cartoony and simplistic, probably to make it more light-hearted feeling, but I'm sure the hardware limitations had a part in it as well. The music seems kind of barebones, with generic tracks fused with some light vestiges of the older tunes. The kid-friendly sliver for a story led to some equally unremarkable boss battles and game ending.
I get the feeling that without a lot of the extraneous baggage that many games come with these days, Retro could probably pull off a sequel every year with purely just levels.