Your sister, Lice, is held inside the Hammer Watch prisons. You must sneak inside and find her.
Beneath the City is a turn based stealth game where each move counts. My initial goal was to create a stealth roguelike using a 3D isometric view.
I finally switched to back to top-down view because of the timing and the controls (3D iso is no good with keyboard controls). Beneath the city lacks proper ending, and different enemies, but all the basics are here.
You can read the full post-mortem of this project.