Picked it up yesterday along with Mega Man ZX:Advent and Mass Effect (got a pretty good amount of money back from selling my school books). I put an hour into it on difficult and made it to the first boss before I got slaughtered. So far it's pretty much what I expected: a throwback to the early PC RPG days mixed in with some hack n' slash. Also if you have headphones, use them, as the game oozes the atmosphere out pretty thickly. Lots of nice sound effects from bugs crawling on the walls, water dripping, doors creaking, etc. Plus the Wolfenstine/Doom look, for me, adds to the experience.
It's a good game for those looking for something straight forward, old fashion, not overly complex, and want to diversify their DS RPG collection. The story cuts to the chase with little bullshit and the bite size levels make it good to play it in small bursts. Also the price dropped down to $20 which is suitable for this game. Now I kinda want to try Doom RPG.