Salnax on 06 October 2013
Taking not only sales but also things like hype, likely legs, and production values into account...
1. The Wonderful 101
2. Castlevania: Lords of Shadow - Mirror of Fate
3. Rayman Legends
4. Splinter Cell: Blacklist
5. Disney's Planes
#1 is obvious, but #2 didn't do much better, despite the much larger install-base. #3 at least flopped across a number of other platforms and has a chance for legs. #4 was possibly the most abysmal, but lacking features. #5 simply did surprisingly bad, even for a low-rated tie-in, across platforms.
Edit: I was tempted to include Demon Training on this list, but that technically was a 2012 release in Japan, and it shouldn't qualify for flop of the year two years in a row.
