Turns out making a third of Inception look like it was pulled out of a game of Call of Duty was no mistake: it was all a set-up for the Inception video game! Director C. Nolan told reporters in Rome:
"We are looking at doing is developing a videogame based on the world of the film, which has all kinds of ideas that you can't fit into a feature film. That's something we've been talking about and are looking at doing long term, in a couple of years."
I'm already practicing repeatedly pressing "A" to startle myself from entering a permanent dream state.