Beyond was not even close to the biggest flop. The true candidates were already mentioned. Fuse is a good solid flop, and my vote would go to W101.
And I'm sorry, but the comments singling out Splinter Cell on Wii U as a flop are just plain stupid. SC was a moderate flop all around, but it had a better attach rate on Wii U than on other systems. Does this mean that PS360 owners don't like 3rd party games? LMAO. Ubisoft questions Wii U support for the same reason SC sold only 30k on Wii U.... there aren't enough Wii U's out there. But saying SC was a flop on Wii U was either a statement with no real thought put into it or an attempt to piss off Wii U people. Lame either way.