From the guys that brought you Diablo - a game just like Diablo.
That might seem a little dismissive were it not for the fact that no-one makes Diablo clones quite as well as the guys that made Diablo. It's what they're good at and they know it. The path to Torchlight has been somewhat torcherous* but fledgling studio Runic Games delivered the goods on a light, fast-moving, loot-heavy action RPG that managed to sate the hunger for Diablo III - at least for a little while.
'Diablo Clone' sums it up more pertinently than would be legally comfortable in other circumstances, but I'm assuming it's all good buddies between Runic and Blizzard. So, we have a structure and layout mashed together from the first two Diablos - one town, one dungeon of many levels, unidentified objects, town portals, health and mana potions, skill trees, sidequests, and an art style heavily reminiscent of Warcraft. Oh, and a soundtrack from the Diablo composer that pretty much is the Diablo soundtrack.
But hey - it's all good because that's kind of what we wanted, and Torchlight kept me entertained for a couple of dozen hours. Not bad at all for a £15 effort from a small studio. It's biggest Achilles' heel in longevity terms is the absence of multiplayer, and after about 20 levels the grind of solo loot gathering does begin to set in quite sharply. However, mod tools were made available shortly after launch and good work is being done by dedicated fans already, so there's ample reason to revisit the town of Torchlight in future.