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Guessed by @S.Peelman
Arguably the game with the densest atmosphere in a franchise known for its dense atmospheres, Prime 2 sucks you into its oppressive world so much that it can be an exhaustive experience too. It was definitely tiring for me in my first playthrough, but I've since come to love and appreciate this game a lot, in spite of its many flaws - like the limited beam ammo, the lacklustre boss battles, the awful key hunt, and most egregiously of all, the dark world in its entirety. And given that the dark world is essentially half the game, that should tell you exactly just how good everything else is. Seriously, if these shortcomings were handled better, this might've very well been the greatest game in the entire Metroid series, which is saying a lot given how this franchise pumps out masterpieces like clockwork. Those shortcomings are there, though, meaning this is only an incredible experience.
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