Coming from a heavy smoker who doesn't do much work out, I could easily explore the cave despite the stairs and a few hike ups. It was overall an easy and fun workout.
However, it is pretty dark inside and can be slippery. So I highly don't recommend bringing your children, but a pair of proper shoes and torch light (I used my phone, it was completely fine, but could be better). The chains and ropes were also pretty old and dirty (from the bat poops).