It's impossible to not love this amazing gem of a game.
The story begins when Samus Aran receives a distress call from a nearby space station. After looking around, it's clear that something attacked and severely wounded many space pirates; some are injured, some are dead. Samus finds data that shows the pirates are experimenting with a chemical substance called "Phazon." This substance has been used to mutate many creatures in an attempt to create an invincible army. The pirates want to be the dominate force in the universe, and they'll use any means necessary to achieve that goal. Samus evacuates the station, but during the escape, she sees Meta Ridley break free from the station, and her suit gets badly damaged. She follows Ridley in her ship to the planet of Tallon IV. Now, it's up to her to re-power her suit and discover what's really happening…..
The gameplay is where the game really shines. You view everything in the first-person (looking out of Samus's visor). You use the A button to shoot, hold A to charge a shot, the Y button to shoot missiles, the X button to go into morph ball mode, and the B button to jump. You can switch beam weapons with the C stick and switch visors using the directional pad. Locking on is simple by holding the L button near an enemy, plus you can point the gun manually by holding the R button. These superb controls make playing the game that much cooler and smoother.
You go through the game exploring different rooms, environments, and even other parts of the planet. Lots of enemies occupy these areas, so you'll spend quite a bit of time shooting. However, as you progress through the game, certain enemies become considerably weaker, allowing you to pass by them or defeat them with ease. All of the enemies you face are totally original and very creative, something that is not accomplished easily. There is always a target location to get to; these locations are constantly updated on your map (the map can be accessed with the Z button). In these special places are suit upgrades, visors, beams, or data needed to progress the story. Of course, you don't have to always go after the newest goal right away. There are tons of extra items and power-ups to find in the game, making for lots of replay value. There are also hundreds of things to scan. Scanning things reveals a lot of extra backround story, and if you scan enough, you can earn an image gallery and even a secret ending. All in all, there is a lot to do.
Some of the coolest moments in the game are the boss fights. Whenever you fight a boss, you are guaranteed to die the first time. During that first fight, you experiment with damage, observe attack patterns, and take in how awesome some of the enemies are when you take them on. Unfortunately, the bosses can hit hard and can end the fight while you're trying to figure things out. Strangely, when you try the second time, you know exactly what to do. All of the fights are innovative and make you think. You'll enjoy every battle, even when they're hard.
The graphics look amazing for a game that came out very early in the gamecube's history. Every environment is huge with realistic elements; the water looks very cool, the caves are well formed, and the snowy sky is breathtaking. No matter where you go, you'll be taken aback by how good everything looks. I especially like how your visor temporarily fogs up when you go through water or steam. The music in the game consists of a few tracks, but those tracks can actually be pretty catchy. There is no dialogue in the game, apart from the stuff you can scan. Even with no words, metroid prime does an excellent job of telling its story (provided you scan things). Sound effects are well done too. Every blast from a weapon sounds awesome, enemies have cool battle cries, and explosions have never been better.
Overall, I would definitely recommend this game to everyone. Everything about it is just so awesome! My only complaint would be that the backtracking between levels can get annoying at times, but other than that, nothing comes to mind. Enjoy!