It's worth playing, it's actually fun, each dungeon is a bit unique, I like to play with friends
The buyable content is annoying to get by playing, but it's actually do-able, and well, spending a few bucks too wouldn't really hurt you.
There's no other game like it, I can assure you. The dungeons (there's about one for every quest), half actionnish feel, hidden parts of dungeons that can only be found with the help of a rogue, other hidden areas, the traps, the puzzles, the places you can only get to by jumping and stuff, this game is unique.