We take it for granted, but the developers in the transition from 2D to 3D were miracle workers. Making a fun 2D video game takes a lot of work and mapping by itself, but then blazing a trail and making a fun experience on a new platform. Granted, it took Metroid a bit longer to make their transition than Zelda, Mario, or Sonic, but damn Metroid Prime is a great game.
What's better is it was able to accomplish it without compromising too much of the classic gameplay that made it so fun to begin with. Turbo Button does a much better job at explaining all this in his video below. It's long but it's worth a watch for sure. Give it a look below.