There are 4 types (elves, humans, orcs and undead). The way you have then again the choice between 4 classes with different abilities. At the beginning you can grow two heroes, if that's not enough, you can then captured the gold to buy new slots for other heroes. So there is much to gain and to explore;)
Only forced the permanent online annoys a vinous (located in the Campaign)! Otherwise makes it but fun and is a nice pastime :)