Battery issues with 13" Haswell Retina Macbook Pro? Extremely fast drain.

I just bought a 13 inch 2013 Haswell rMBP (i5 2.6GHz, 16GB RAM, 256 SSD, running Mavericks), and appear to be having battery issues. Playing X-Com: Enemy Unknown at 40% brightness with nothing running in the background completely drains a full charge flat in just two hours. When watching a video with nothing else running in the background, the time-remaining estimate from the battery status bar continually drops at a rate much faster than it should chronologically, say 10 min estimated time / every 2 minutes of real time. I've booked an appointment at the Genius bar, but wanted to know if this is in any way normal? Tests in reviews I've read seem to indicate that these are unusually fast drain times for such use. Thanks!