Those of us who used to play old versions of Counter-Strike back when it was the only competitive shooter on offer, will surely remember hearing about, or even playing the cyberpunk-themed mod, NeoTokyo. The mod was released way back in 2008 but has only now been added to Steam.
You can grab the free download from here. Being a standalone mod, it will not require you to get Source SDK or have any Source-based games installed.
Just to remind you of how cruel but satisfying it was, you can have a look at the gameplay video below, courtesy of YouTube user TheLonewolf199.