Well, guess I should keep things short as I didn't play this much anyway...
I wouldn't say this is a bad game, it seems like an alright time-killer, but I simply couldn't get into it.
It's a very simplistic sort of an arcadic-strategy game, you'll get the hang of it fast enough with the tutorial (assuming you just read it all quickly and skip the weird dwarf monologues).
You basically have dwarves under your control and have to dig around, make them rich and protect their\your base from danger.
Again, can't say that's a bad game, yet I could think of some better ways to pass my time rather than watching dwarves doing an endless mining jobs and walking into their deaths in some water\lava\monsters caves. But that could be just me.