Good subject.
We're talking about two anticipated games, one was supposed to be a launch title and the other have a release date closer than what we were hoping.
As of now we can compare these two games. I don't read anyone saying that Microsoft make games generally for the same kind of gamers, we can already say that Halo 3 is for the same kind of people who bought Gears of War. Halo 3 will surely 5 million copies in the first months, but the sale will slowdown really fast two just like Halo 2 and Gears of War. Huge Sales in the first months of many millions copies and a rapid drop in sales not to long after.
We also have to take in comparison that Halo 2 was the sequel to a great game so people were aniticipated it, but many were deceived : great multiplayer, poor single player. Also many people are deceive by the Beta right now, so I don't think the sales if Halo 3 will reaches those of Halo 2.
For Metroid it's an other story, the first one was surely one of the best games ever. The advantage of Metroid is the fact that he is one of the few Nintendo games on the Wii, and see the crap third party's are porting on the Wii right now Wii owner will jump on it, so expect Corruption to sell the same amount of copies of Zelda on Wii, he will easly sell more than the first two games. Add on that that fan of the series will buy it, but if Nintendo's marketing don't change and that the game is the exemple of how FPS play on Wii, he can attract some PC gamers to.
I'm not sure Metroid will reach the sales of Halo 3, but he as the potential to and he can also have higher sales, but again we can't make any prediciton with any Wii games. One year ago, many people were saying that Nintendo was doomed, and what happened now, the Wii is the fastest selling console, any game from Nintendo can reproduce these kind of situation.
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