Finally seeing the DKC games again, huh... let's just hope they release in the US too!
They aren't as good as the SNES games, no, but they do push the Game Boy pretty hard. DKL1 is a fairly simple game, and is entirely different from the SNES game. It has four worlds, inspired by worlds from the SNES game, but with more levels in them than the SNES worlds (because there are fewer of them). It's good but not great; I got it back when it came out, but never bought its sequels until much more recently. DKL2 is an adapted version of the second SNES game, so it's very much like the SNES game but with altered levels to fit the GB's screen resolution. Because it's less original, it might be the least interesting of the three, though otherwise it's pretty good. DKL3 is sort of like DKL2 in that it follows the world order of the SNES game, but story-wise it's a new game, not a remake like DKL2 is. The levels look familiar, for anyone who's played DKC3, but are redone, more so than in DKL2. It's good, maybe the best of the three.
Overall though, the biggest problem with the DKL games is that that kind of graphics, with CG-animated sprites over highly detailed backgrounds, isn't a good fit for a handheld. Enemies blend into the backgrounds CONSTANTLY! The problem can be solved with the actual carts, because in a GBC or GBA sprites and backgrounds can be displayed as different colors, but GB VC on the 3DS doesn't support that because Nintendo is incredibly lazy, so it'll be back to black-on-black confusion, I guess. Annoying. They're still decent games, though... but I like them more on GBC/GBA due to the addition of color. And on that note, the DKC remake for GBC, and that Japan-only GBC version of DKL3, would also be pretty great to see...