The third-party game footage shown during Nintendo's E3 press conference this week to demonstrate Wii U was taken from PlayStation 3 and Xbox 360 code – but at least one game is already up and running on the new console.
And it looks just as good on Wii U as it does on PS3 and Xbox 360.
That game is THQ's Darksiders II, which developer Vigil spent five weeks building for Wii U in anticipation of a reveal at E3.
"We have Darksiders II completely running on the Wii U right now," THQ core games boss Danny Bilson told Eurogamer today.
"It took about five weeks. Coming into the show we were ready to go. We could have demonstrated it on the hardware but they [Nintendo] decided not to have full games shown in the booth."
Instead, as confirmed by Nintendo this week, PS3 and Xbox 360 footage was shown to reveal that Darksiders II is set for launch on Wii U, due out next year.
"But if you were to go into Vigil in Austin, Texas right now, Darksiders II is fully running on the new hardware," Bilson continued.
"The Darksiders team was one of the first teams to get dev kits. We've had dedicated engineers on it working seven day weeks leading up to the show.
"I've got all the emails. We now have it running with the controller. So we could have shown it."
Nintendo is yet to fully reveal the Wii U specs, making power comparisons with the PS3 and Xbox 360 difficult.
"Some of it is still in flux," Bilson said. "There are still some improvements to be made to some parts of it."
But, the Wii U version of Darksiders II will "absolutely" look as good as the PS3 and Xbox 360 versions.