M
I didn't fully "buy" the romantic angle between McConaughey and Hathaway, it's an additional love angle the movie didn't seem to need. In fact I'm not sure I totally "buy" he was in love with her beyond, "Hey, we're pretty much the last two humans out here.... Wanna?"
Maybe I missed a nuance in there but I just didn't get a romantic angle between the two so not sure I feel the "power" of the ending with him going back through the wormhole in order to meet-up with her on the destination planet. (And I still don't quite get if the wormhole was there or if he was going to make a shitty-long trip to get there, as well as the rest of humanity on the "arks."
I didn't get any romantic vibe from that at all. I just figured it's because he found out she was still alive and was likely the last person from his time that he might still have a connection with her.