Hawki said:
Zelda, I think, would be easy. In fact, due to how each game is self-contained from the others (bar the occassional sequel and reference), you could easily fit a LoZ movie on the timeline. And with that in mind, you can do whatever story you want, and tell it however you want. Cut out the 'gamey' bits, focus on story and character, and voila. You'll probably have at least a decent fantasy yarn. The main problem I'd say is hearing Link speak. Because...well, y'know...
Since The Last Airbender, we know there is an audience for "serious" kid-oriented animated serie.
Even Dragons and MLP/Littlest Pet Shop/Ever After High are doing it.
Um...eh...
In a Metroid movie's defense, I'll say that there's a precedent for more conventional storytelling if one considers the manga for instance. But in fairness, Metroid has a few things stacked against it:
-Most of the time, Samus is on her lonesome, and in a suit. So not only do you need a single character/actress capable of carrying a film by theirself for most of the run, but the visor, unless they do the Iron Man trick that's also been copied by Power Rangers, will hinder storytelling through body language.
Moon.
Give a voice to Samus's spaceship and go Cowboy Bebop.
As for the body language problem: Zero Suit.
-Metroid takes a fair amount of influence from Alien, at least in regards to setting and arguably themes. It's the same problem that Prince of Persia and possibly Warcraft had/will have. They're wearing their influences on their shoulder. We've seen swords and sandals in films for decades, and orcs are...well, orcs, even if Warcraft does something different than Tolkein.
Aliens, bounty hunter mode. It has never been done before.
The predators themselves aside.
-A film set in the Metroid universe with Samus as a someone in the background could work, but the general reaction to Federation Force seems to have shown that Metroid fans don't want that. I know there's other factors for said reaction, but, yeah. It also doesn't help that Other M is also frowned upon, when that also tried more conventional storytelling.
Give us a curvy bounty hunter, running after alien-ultimate-weapon pirate stealers, Ninja Scroll style with lasers, and we're on.
-Finally, as I've discussed elsewhere, I don't think the Metroid games I've played have ever been strong in terms of plot, apart from Fusion. It's part of why I've never been as enamored with Metroid as, say, Zelda. The Mario RPGs aside, would anyone clamor for a Mario game based on its story? Probably not.
Show, don't tell. Metroid has always been very good at that.
Well... until recently.
The only light at the end of the tunnel is the fan film "The Sky Calls," but imagine making that feature length, and accessible to the general audience. And even that film is using 2001: A Space Oddysey as its frame of reference, and while I'm not fond of 2001 myself (like the book though), trying to top that would be a rigged game.
See Kawajiri/Gainax anime style.