Much of the challenge in cityglitch comes from you not being alone. Denizens lurk on the rooftops, some being deadly, and others merely being roadblocks. The latter can prove handy in obstructing a foe that will kill you with a touch, or be a hazard when they end up plonked on a rune, and cannot be shifted.
The key is understanding the puzzle behind the puzzle – which creatures respond to your movements (and how), and which just go about doing their own thing.
Most games of this sort ram a tutorial down your throat to explain everything, but cityglitch hurls you in at the deep end. Oddly, this is more satisfying – figuring out how everything works is part of the fun.