As fun as the game is, it will not appeal to people who dislike pinball. This is a stand-out from the normal games.
Gameplay (7/10): The first thing to notice is that this is a pinball game, so the controls are very simple. You have left flipper and right flipper, set to different buttons so that you can get comfortable how you wish. You also slide across the touch screen to tilt the table, it makes perfect sense (though tilting the table is difficult to do in a heated situation, which makes it unwieldy and should have been programmable to the buttons). There are some added twists though. Along with the standard pinball fair of bonus multipliers, jackpots, bumpers, etc., there are also Metroid things added in. There are enemies that you can attack by hitting, you can lay morph ball bombs, you can shoot missiles once you get into combat mode (a mode where you stand up near the bottom flippers and shoot at a bunch of enemies for bonus points) and you can use a power bomb for quick screen clearing. All this adds up to make the pinball game a little more interesting than the plain old pinball we are all used to (there are enough 'normal' pinball games out there, so it is refreshing to find something unique). You will even be able to 'fight' some of the bosses from Metroid Prime, and your main 'objective' is to collect all the Chozo Artifacts so that you can get to the Impact Crater and fight against Metroid Prime itself. It all makes for an interesting diversion, but the fact remains, this is still a pinball game.
That being said, the extra features are neat and mix things up, but the truth is, you really only have two proper tables to play on. The other four tables (that I have discovered) are all boss battles and aren't just mindelss fun pinball tables. Having only two proper tables is a little unnerving, but I have played for hours on the Tallon Overworld table and still haven't gotten tired of it for some reason. As said, in the end, this is still a pinball game...albeit a very fun pinball game, but it is still the monotonous, high-score acquiring type of game.
Graphics (10/10): Actually, this game loos GREAT. All the stuff is fluidly animated, well crafted and each area looks unique. For a pinball game, a lot of work was put into making this game look beautiful.
Sound (9/10): The music is top-notch. They are remixes of various Metroid tracks (mostly Prime, but there is at least one old-school Metroid track) and fits each table perfectly. The sound effects are very much like a pinball game while still retaining the wonderful Metroid sounds. Overall this is a great sounding game, though the sounds that come out of the included rumble pak don't have a controllable volume and can get annoying sometimes.
Value (8/10): As said, with only two real tables, there isn't much to do here. You can try doing the boss tables at fast times, get high scores in the normal tables or just go through the 'Multi Mission' (aka story mode) mode and try to get a high score before you have to defeat Metroid Prime. It isn't bad, and the inclusion of single pak 8-player multiplayer is really nice (on a table I haven't discovered in single player yet: Magmoor Caverns), though it would have been better if there was a multipak so that you could play on ANY of the tables.
Overall though, if you are a pinball fan, casual or hardcore, this game will likely entertain you for a long time to come. For all others, try before you buy, because pinball is not for everybody. Enjoy.