I wouldn't say IGN made it. Rainfall Films did. Sure, the actors are a bit off (can't really believe that lead guy to be Link, although he totally nails Link's vacant stare from the N64 game).
I thought the trailer was amazing, unusually well-done for a prank. And exactly, a film done with the purpose of being as faithful to the videogame as possible would, well, be more faithful to the videogame. It would please fans of the game. But then the differences between videogames and movies would probably hurt the film (if you don't enjoy watching a friend play the game, you won't like watching a film about it either). Critics who have never played recent videogames will likely say nasty things about it, although I'd be interested in a Metal Gear Solid movie just to see if the hours of cinema scenes end up being a passable movie when combined. Plus, Roger Ebert liked the movie version of "Hitman" for some reason.
Also consider that when playing a videogame, you sometimes wonder about the parts of the story that aren't in the game. Or wish to change existing cutscenes. You may have dreams about these alternate sequences. So fans will want to see these extra little things, otherwise it's not much more than capturing gameplay from the game.
And fans don't want to see the parts of the game that just plain didn't work out. I don't want to see Darunia shaking his groove thing on the big screen.
So the movie has to be different in any case. Catering to fans unfortunately means the audience will mainly be fans, and that's too small an audience to cater a movie to. To people who never knew what a Goomba or a Koopa was in "The Super Mario Bros. Movie", they enjoyed the film more than fans who went bat-crazy nitpicking over all the mistakes (never in a million years would I accept a Goomba as being six feet tall. But other people will think "goomba = mafia guy" and it's no problem to them. And they don't know or care that Yoshi is supposed to look very different). If you cater a videogame movie to videogame fans, then the mainstream won't quite understand why we have to watch Link painstakingly grab three jewel/emblem things just to get to the Master Sword. Ash from "Army of Darkness" would just chant a few magic words, forget the third word, cough through it, then grab the book and get out of there.
That said, a Prince of Persia: Sands of Time movie would be cool. Had a great storyline, had lots of action through fancy acrobatics, get to throw in the special effect of going back through time. I don't see how it'd be impossible to make a good movie out of that.