Corruption is a phenomenal game in many ways. I played it from beginning to end and didn't feel I wasted my money. Yet when it was over I felt weird. When I first played the original Metroid Prime back in 2002 I was flabbergasted at its fictional depth. Nearly everything in the world could be electronically scanned and analyzed for information, much of it serving no purpose other than to make the game world feel rich and complex. This is how gamers discovered that metroids, the legendary life-sucking monsters from which franchise gets its name, had a philosophical dimension.

Normally "life" in videogames is an unexplained convention. It's an arbitrary way to measure how many times an avatar can get hit before she dies. Traditionally when metroids touched Samus she would begin losing life until she died. However, Metroid Prime revealed this phenomenon to be a mystery even to the characters within the Metroid universe. Scientists were confused that metroids didn't seem to suck blood, oxygen, or any other essential element out of the human body. Yet when the metroid was finished, the subject always died. No one could figure out what the metroids were sucking out of people, which left science at a loss to explain how they functioned.

I found this detail marvelously fascinating. The writers at Retro, the American studio which had taken over the franchise from Nintendo, had in one subtle stroke smuggled metaphysics into the Metroid universe. This was a series which freely tossed around names like "Space Pirates" and "Mother Brain." But suddenly Metroid was being imbued with a new kind of complexity. This delighted me to no end. I couldn't wait until Retro's next Metroid game to see what directions they might take the series.

Flash forward six years. Retro's Metroid Prime trilogy has concluded, and to much critical acclaim. Yet I'm wondering what happened to the game I played in 2002, the game that seemed interested in more than just exterminating some baddie in the name of being awesome. What began as a rich plethora of open ended questions about life, the universe, and everything all boiled down to our boys in uniform squashing bugs. Imagine if a wonderfully atmospheric sci-fi film like Alien had a sequel where they just called in the marines and... oh wait.

Ok, so Aliens was a great sequel even if it did downplay the mystery of the original. But Aliens was, at the end of the day, about something. There was lots of bug squashing, but it was also a sharply written story about a woman going through a personal transformation... and it was a transformation one could trace back to the original film. There is no subtext of this sort one can draw out of Retro's Metroid Prime trilogy.

Nintendo's Metroid games are a different story. If you look at the four Metroid games made by Nintendo you can actually trace an arc, a shift in perspective that Samus--and the player by extension--goes through. The original Metroid was about discovering that metroids were dangerous creatures. Metroid II was about their virtual extermination for the good of mankind. Yet in Metroid III we discover that metroids have emotions and are capable of forming complex social bonds. And in Metroid IV we discover that hunting them to extinction destroyed an ecosystem in which they were serving a benevolent purpose: to keep a much more dangerous organism in check. This is why when we last left Samus in the Nintendo's Metroid series she had infused herself with metroid DNA in order to survive, thus becoming what she had sworn to destroy. She was also left at odds with the Federation, which tried to kill her once she discovered they were doing illegal weapons research. The Metroid Prime series, by contrast, contains no such reversals or ambiguities. It's just, by the end, a straight up story of good versus evil complete with cavalry and fanfare.

For someone such as myself, who revels in games that inject compelling content into pulp genres, the Metroid Prime trilogy feels like a missed opportunity. Retro's original Metroid Prime did the improbable task of taking a classic videogame franchise and expanding it into a rich fictional world with literary potential. Had it continued along that trajectory Metroid Prime 3 could have been closer to Bioshock than to Halo. It could have been six years of videogame history that had more to say to the world than just "Misson accomplished, solider."