I have finished my 3d playthrough of this game and have really enjoyed it.
As I previously stated its pretty much like the previous two Risen games and almost like a continuation of Risen 2.
There are several islands that were visited in Risen 2.
The reason for my 3 playthroughs was that there are 3 factions you can join, and of course you can only join one. Your combat style though doesn't change no matter which faction you join. You can basically use the same spells and melee or ranged style no matter which faction. You just can only learn spells related to your faction but can buy scrolls or runes that accomplish the same thing.
Although rather pricey you get a lot of play for your bucks.
Now it's time for me to catch up on some of my adventure games while I wait for DA Inquisitor which is due out in a month and Witcher 3 which has been postponed again until Feb 2015.
(Hard to imagine I am typing 2015 When it seems like only yesterday that 1996 was a long way off. Oh well,,,,,,,,,,,,time marches on)