I'm actually fairly hopeful for this film, I think it's much more likely to end up as a Prince of Persia than a Max Payne or Hitman. The things that make Deus Ex: Human Revolution iconic are it's visuals, it's theme and it's setting. It's gameplay can be adapted into any sort of action-spy-thriller. And most importantly, what gives it an edge over PoP is the franchise is less splintered in style and a new Bladerunner rip-off is long due.
Whereas Hitman and Max Payne were much more focused on their gameplay and the iconography of their gameplay. It's much harder to translate to film in any non-terrible way.
Of course Prince of Persia wasn't a fantastic film. But it wasn't awful.
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I actually think Christian Bale would be good in the role. He's got intensity absolutely down and he could rehash some of his Equilibrium. But most of all I think he could manage to convey that stoic-judging that Jensen does. Jensen doesn't say much or act out, until the end, but he's watching all the time, taking in the world and forming judgements on it. He doesn't know what he is or what his place in the world is. Christian Bale could do it.
I don't think he would be keen to act it though. I think he tends to be looking for more prestigious roles, particularly now he's presumably rolling in money.
I could see Keanu Reeves too, he'd get the coldness right and bearded Ronin-Reeves could look the part too. The problem is if it feels too Matrix-y. He's not quite as great at conveying emotion behind his coldness either.
Michael Fassbender or Viggo Mortensen would be other good choices. Again we're probably not going to end up with something as classy as that