Immersive cinema / theatre etc type experience - what is it?!

[CheerioBeerio]

Can anyone describe to me exactly what an immersive experience is?!
I've come across a few ads on Facebook for immersive experiences, some seem to indicate glow in the dark lights and others just mean actors talking to the audience. What exactly is it and are they any good?!

Depends, and there isn't really an "exactly".

For example, I've been to a couple of performances (Punchdrunk amongst others), where you are free to wander randomly around a building discovering bits of the story, or not, on your travels.

I've also been to a couple of seated binaural performances, where you wear earphones and the sound is delivered directly into your ears. It makes it feel more 3D, as you can hear the distance things are happening at. One of those performances was in pitch black, which was creepy genius, particularly when it sounded like one of the characters was whispering directly into the ear.

There are probably all sorts of other ways of making the experience immersive.

Are some performances better than others? Yes. Are some badly thought out and actually quite poor Yes, again. Were they fun? I thought so.