I originally bought this game when it was released on Desura close to 2 years ago, and have put many hours into it.
It's a "pseudo-turn-based" game, where you can run around with the WASD keys like a platformer, but enemies/NPC's only move and attack while your moving and attacking. While you are not doing anything, neither is the enemy. In a way, it's kinda like FTL in that regard. Kinda.
For those familiar with roguelikes, Wazhack, as the name suggests, takes a lot of inspiration from Nethack, to the point where it might be easier to describe it "2.5D Nethack". You can see it in the items; the way they are identified, cursed, blessed, enchanted, etc..
That's not to say that it's a clone though, Wazhack has MANY of it's own features that I don't want to spoil for everyone, and even has branch dungeons and many different enemy models and spells.
There's even going to be a multiplayer like feature, though not in the traditional sense.
If you like roguelikes, Wazhack is definitely one to pick up.
EDIT: I hadn't played this game for about 5 months, and the game is even better than it was back then. Loads of new content, including items, events and even classes were added. There's also been even more balance changes. The game was far more fair than Nethack ever was, and now even more so. Just the right amount of fairness and challenge.
For beginners, the Barbarian/Vandal is a great class to start with due to their high health, damage, and starting weapon. You'll have trouble finding armor due to their large size, but their high health makes up for it. By the way, you can tell if your Barbarian/Vandal can use armor if the armor in question has something along the lines of 'very large' in parenthesis underneath it's name.
The only thing I really consider bad in this game is the pet AI(every class starts with a pet). While it's certainly leagues better than Nethacks, they're terrible when it comes to running across ladders, though they're better now than the last time I've played. I also wish you could set their aggressiveness like in Torchlight 2. Honestly, they're not all that useful, but they're nice company in that lonely dungeon. I also wish you could choose which pet to take, rather than each class having it's own pet, though I understand the reason behind that.
For those who want to try before buying, go to it's Desura page here:
http://www.desura.com/games/wazhackOn that page, click the blue "Free" button next to demo. If you don't want to use Desura, simple click the Free Button and look for the link that says "Download Direct", and you'll be able to download the standalone demo installer.