I'm going to assume that Torchlight for the XBOX would be a waste of time. I enjoy the game for the PC, and I believe I have over 40 hours played on Steam (which I cannot check at the moment). The problem is... the game has flaws, and the flaws create some rather big annoyances. The flaws are somewhat mediated by mods to the game, but I doubt you'll get mods on the 360.
So, without mods would I pay $15 for the game? I'd be leaning toward probably not. $5? Yeah, sure... the game's descent into the mines is fine with the flaws, but once you start crawling through the infinite dungeon, you realize how things such as the terrible money sink known as enchanting combined with the utter lack of money in Torchlight really hinders you.