That is a great point. There were many amazing games that sold less than 5 copies when originally released even though they were critically acclaimed. Over time they developed a cult following and some were rereleased like Ico, Shadows of the Colossus, Beyond Good and Evil, Okami Wii, etc... but then you have others like Heavy Rain, Enslaved or Zack & Wiki Quest for Barbaros that very few bought or appreciated and it is a shame as Heavy Rain/Enslaved could have had sequels if they did not lose money on those games due to poor sales. I am not saying Wonderful 101 is at the level of the games on this list, but it is a great game that you could only conceivably play on the Wii U. Not even the 3DS could do this game justice and forget the Move or Kinect. This game was made for the Wii U and for those that feel the system is a gimmick toy, they probably did not buy this game before they made that statement.
Heavy Rain made a shit load of money for Sony. That's why Beyond Two Souls is being developed as a Sony exclusive. I personally think Heavy Rain is very overrated. While its unique, it's a game that absolutely hinges on its story and the story is weak, filled with plot holes, and poorly acted. Just my two cents.
Back on topic, this game is on my radar, but for much cheaper. I played the demo twice and still barely knew what I was doing. They did a terrible job explaining how combat works, so that made my decision to wait easy.