There is a retail version of Torchlight on PC, at least (see here), but I think just a digital download on Xbox. I tried the demo on the Xbox, but it is cheaper on PC; IIRC it is 1200 points on Xbox, so CAN$17 here (but I would have to buy a $20 card to get it), while the PC digital download is listed as US$15 (sometimes going on sale) and Amazon.ca has the PC disk version for CAN$10.

Isometric is a top down view, but 'top down' is a more general term; isometric refers to a particular camera angle, as used in Diablo, Divine Divinity, etc.