It is fairly safe to say that Wii U owners are still disappointed at the delay of Rayman Legends, which was scheduled to be released at the end of this month. Even more so when it became clear that the game was complete and is being delayed for no other reason than to wait until the other versions are ready to launch in the same month that GTA V does.
In a video posted by the development team the developers at Ubisoft Montréal apologize for the delay and announce that they are putting the game's Online Challenge mode out, as a free download, exclusively for all Wii U users. This should become available sometime this April.
The Online Challenge mode is far more expansive than a simple demo. Challenges will be generated daily in five different settings. They will have online leaderboards and the developers themselves are promising to be playing as well.
While Wii U owners would likely just want to be given the opportunity to buy the game now, getting a part of the full game for free in spring is (technically) better than nothing. Whether or not this is enough to mend some fences with Rayman fans... we will have to wait until April.
It's not like Wii U owners aren't used to waiting at this point.