Does it get any better then this?
The exploration is the main aspect of this game. You can go almost anywhere. Some suit power-ups are required, and you can switch between beams. Sometimes it feels more like a roleplay then the other games of the series. Sometimes you feel scared, sometimes you feel alone. The feelings this game gives you sometimes are quite amazing. It's less of an FPS and more of a First-Person Adventure game. But honestly, Nintendo knew what they were doing with the first 3D Metroid game by hiring Retro Studios to do the job.
In short, buy it. Now. It costs around five dollars now, and trust me, it's worth every penny.