There are four acts in total, although the last two are more rushed than the first two. Act two is way bigger than one and I would recommend looking at a level map if you feel stuck somewhere, since fights with higher leveled enemies are mostly just impossible.

For me, a lot of times it is just like a demo of the olfen days. I play a bit and then decide if I want to buy it. And if not then I have had some fun at least.