Feels a bit like Front Assist that Little John mentions. Uses the same radar but will slam the brakes on if it reckon that on your current velocity / may be acceleration a mere human isn't going yo be able to break. Bends it sometimes gets that wrong if you are turning so will see a bank and reckon you haven't seen it. Gives a warning before dramatic breaking.
ACC probably works better with DSG since it will take the car through the gears dropping speed using engine braking. May be with a manual you might get Little John's effect.
Largely don't use ACC myself, used traffic jam assist that the car has once ?. That's handy on stop / start slow moving traffic. Was an option on 2016 some Atecas.
Learn more about how Traffic Jame Assist makes driving easier & more comfortable by automatically accelerating & braking when driving in a traffic jam.
www.volkswagen.co.uk