Torchlight is a hack n' slash dungeon crawler like classic Diablo, but it bears a lot more resemblance to Fate, which is not surprising since the now defunct Runic Games was formed by Travis Baldree. As such, Torchlight contains some differentiating mechanics like a selection of generic spells that any class can learn on top of their class specific skills and the player also has a pet by default that aids them in combat, can travel back to town to sell items and be transformed into more powerful forms by feeding them magical fish.
I like the Torchlight series because it feels like a classic hack n' slash, but generally more fast paced, and there's a lot more freedom when designing a character than with the usual rigid class system most ARPGs have, barring the lack of a respec system.
That being said, it's kind of hard to recommend Torchlight 1 when Torchlight 2 is superior in pretty much every single way. It's not like there's an overarching narrative to follow or something like that, there is a story linking both games, but it doesn't really matter to be honest. You wouldn't lose much by skipping this one in favor of the sequel.