My daughter got this as a Christmas present, we spent just over an hour doing most of the experiments, some were more successful than others. The slime went down well, as did the volcano, but the lava lamp was a bit of a damp squib, even though we tried twice, the fireworks were pretty but not much to them, and due to the weather we didn't do the other two experiments.
On the down side the sand is pretty much there to give a bit of weight to the box it doesn't add anything to the volcano experiment, except extra washing up, the food colouring didn't have any lids on the tubs so once you had broken the seals on the little tubs that was it.
But we did happily pass an hour or so.