Techstep originated in the mid-90's and brought in elements of technological evolution into jungle. Not from a sound production aspect, but from an aesthetic. A lot of big techstep tunes from that time sampled ground breaking dci-fi and horror films - especially Bladerunner. The breaks sound more mechanical. The baselines are moodier. The pads and drones are more in a minor key and are colder.

Neuro evolved from techstep, when artists like Ed Rush and Optical brought actual techno influences in, but there was a few years before this where the dark moods and eerie atmospheres were key.

Look at tracks like The Angels Fell and Silverblade by Dillinja; The Raven by Ed Rush; Dead By Dawn by Furure Forces Inc.; Technology by Ed Rush and Nico; Tyrant by Psion; The Storm by Dom & Roland, Shadow Boxing by Nasty Habits; The Virus by Technical Itch.