The most obvious thing about this game that caught everyone's eye was the graphics. When it first came out, WOW, it looked beyond anything the world had ever seen in the world of gaming. Once you actually sat down to play the game, you found that an excellent platforming game was underneath the pretty wrapping.
It wasn't as fluid or fun as the Super Mario games, but it had a style all of its own. Whether you were leaping from one place to the next or hurling objects are your foes, you felt like you were a big fearsome gorilla (is that what DK is?). The gameplay was satisfying and challenging, but your eyes kept saying, "Go on, I want to see more!"
I don't remember this game having revolutionary gameplay or especially memorable moments. But when you think about a game that revolutionized graphics in the early SNES days, this was it. Thankfully, the game itself was fun enough to warrant the high praise it's received.