Sources said graphical quality "won't be a problem" on Nintendo's new console, but a drop in CPU horsepower compared to 360 and PS3 could see Wii U lag behind in areas such as complicated physics and AI.
A second source working on a big name franchise said GPU and RAM power "won't be a problem" on the new console but, again, claimed Wii U struggles to match PS3 and 360 in processing power.
"We're still working on dev machines but there have definitely been some issues [in porting PS3/360 games]," our source said. "It's not actually a problem getting things up and running because the architecture is pretty conventional, but there are constraints with stuff like physics and AI processing because the hardware isn't quite as capable."
The same source concluded, bluntly: "I suppose you don't need sophisticated physics to make a Mario game."