Don't take it too serious. It can frustrate you badly.
Metroid Prime: Pinball is, obviously, a classic pinball game with strong elements from the first FPS/adventure game released by Retro Studios in 2002. The boards are all themed with enviroments found in planet Talloon IV, and also very well designed and close to the original looking. There are lots of foes, like parasites, space pirates, triclydes (so annoying), beetles, and, of course, metroids. Some bosses, like Omega Pirate and Ridley, also appears.
The main game (I mean: the "Multi Mission" mode) consists on entering simultaneous boards in order to earn Chozo Artifacts. Yeah. Like in Metroid Prime, you'll need twelve of them to unlock the gate at Chozo Temple (wich is also one of the six boards available on this game) and beat the game. There are some spots on each board with a holographic projection of some enemy, and you have to kick your ball there to complete a task (eliminate a certain number of foes) and get an artifact. This is the frustrating part: the spots aren't that easy to reach and your luck will count on most part of time to complete the mission. Fortunately, you have some gadgets that may help a lot:
1- The morph ball bombs: available since the beginning of the game, while morphed on a ball. Press 'B' to release one of 3 bombs. They'll recharge automatically after a few seconds.
2- The power bomb: you know this one, right? Push the Y button to release a powerful wave wich destroys every living being on the board. Well, except the bosses, obviously. This is a rare item and you can use it once after unlocking it (it's possible to recharge only if some monster drop 'em).
3- The missiles: when you unlock the "Combat Ready" feature (a spot on the middle of the board where you can fight as unmorphed Samus), you can shoot them at monsters. Like the power bomb upgrade, this must be unlocked on a certain board to become available.
The "Single Mission Mode" is a bit different from the "Multi Mission Mode" described above. You can't warp to different boards and there aren't artifacts as a reward for a mission completion (you get some emblem called "special" instead). The Pendrana Drifts, Phazon Mines, Chozo Temple and Impact Crater boards are a time trial challenge (you start with all upgrades and 0 lives to defeat the board boss as fast as possible). You can't either beat the game through here.
Timing and luck are the core of this game. You can shake the table by tapping the lower screen of your DS, but this won't work precisely all the time and isn't really a solution for random failures. Your ball may also reach the lower pit randomly after kicking on some monster or spot from the board. These phisics are valid, of course, but they may also ruin your hard work (trust me: I died many many times while trying to reach the 12th artifact). It's all about luck at all. You can get a few extra balls (extra lives) during the game and there are two ways to earn 'em: by a random prize on slot machine spots or after reaching a certain score (2,000,000 points, 5,000,000 points...).
As a pinball game, Metroid Prime: Pinball delivers a lot of fun. With frantic action and various paths, missions and enemies, it won't get old that fast (trying to break high scores is really addictive). But, as an adventure game, it turns into a complete frustrating experience. Don't take it too serious.