Not only am I against this particular video game movie, I'm against all video game movies.
First of all, making movies out of video games could only be sorta-kinda justified ten or fifteen years ago, when we didn't have practically photorealistic graphics and the typical game character appeared to be made of Legos.
Secondly, most games with a story worth telling tend to do a perfectly good job telling it themselves.
Third, games are not movies; you're meant to be an active participant, not to just sit back and watch. (Insert standard cutscene-heavy-JRPG-bashing snark here.) This is especially true with games like Mass Effect. The whole fucking point is that you are Shepard, this is your story, and you have to decide how it goes. Take that away, and it's basically just another sci-fi shoot-em-up.
Lastly, video game movies suck. They all do--every single one, without exception. They always have, and they always will, because they're made by Hollywood, and Hollywood doesn't give one-tenth of a shit about the subject material. Movies are made out of video games for the same reason that movies are made out of old TV shows: because studios figure that name recognition alone will get people storming into theaters. (Sadly, they're often right.)
If you want to approximate the experience of watching a video game movie, just watch over someone else's shoulder while they play the game. Or watch a playthrough on YouTube. Either way, you'll save yourself the cost of a ticket.
