Best $5 I've ever spent easily. Very addictive game and deceptively deep gameplay. Loaded it up only meaning to "try it out" and ended up playing for 4 hours . I was doing pretty well on my third run through (first two ended in about 5 minutes)... lasted for a couple hours, before getting mobbed on level 2, popping an invisible potion to run off, getting away safely, and then walking over a trap shortly thereafter while trying to get my health back. Will definitely be getting the expansion packs . I can see the appeal now of the roguelike genre for sure. This is infinitely more fun to me than Diablo 3 or games of that ilk. (not completely related, but they're dungeon-crawlish too)
Hope you enjoy your stay. I think the main difference between Roguelikes and other dungeon crawling games is that they are more like puzzles than running around and blowing everything up. There's decision making that can totally change whether you live or die. It's more satisfying then simply mashing buttons. You get to earn your success.
It's by far the best value for the $ of any game I've ever bought, period (second would be The Binding of Isaac, another rogue-like of a very different flavor). The pocket dimension was such an amazing addition to the game too. I never touched crafting before they added it in, and vendored tons of useful wands/etc that would have come in handy later. It was such a clever thing for them to add.
The Diablo series was actually originally inspired by rogue-likes, and at one time was going to be turn-based. But somewhere along the way, they changed their minds about that.