PC community is bigger and more diverse than xbox community. Every genre here has it's players. Not everyone plays stracraft, curses consoles and worships Gabe Newell. If something like Isuka can find its customers (i like it actually) despite all pointless hate (any game gets pointless hate), Overture has all chances to earn good sales.
Xbox... Halo, Gears of War, kinect, casual family gaming... gets animu (!) slasher (!!) with RTS (!!!) mechanics.That was horrible choice to release it on this platform.
Plus i think mediocre indie game on steam with trading cards and achievements will have better sales than Overture on xbox...