I've never played Lock's Quest but I've heard it compared to that.  From my own experience I can say its a lot like Desktop Tower Defense, and Pixeljunk Monsters.  There is a lot of dialogue, but if you read it, its actually pretty funny.  Like when the Mayor ask the Ninja Master how many demons there are, he brings over a "Ninja Consultant" to compute the final number.
Seriously, just give it a shot.  The demo is pretty robust as you get to play through 6 levels.