Alright, here goes (A few spoilers)...
-This game REEKS of poor design choices. The combat is the clunkiest I've ever seen in any game ever (even worse than the original Risen which was also pretty awful).
-The difficulty curve starts off as a brick wall that turns into a damn cliff once you get over it (as in, it's hard as balls at first, then it becomes laughably easy).
-The first "real" boss at the Earth Temple is interesting but then every other boss in the game save for the second to last (which uses the EXACT same mechanics as the Earth Temple boss) is just standard swordfights.
-There are exactly two characters that are even remotely memorable throughout the game, and they both either die after the first boss or are as useless as voodoo.
-Oh, and Voodoo is useless except for the points where it's shoehorned into the plot and you have to learn it and use it from time to time.
-Money is damn near impossible to come by early on, and any time you DO have money you have to throw it at a skill trainer to learn the basic freaking skill set for your desired weapon(s) because SOMEHOW the player character forgot literally -EVERYTHING between the first game and this one.
-Speaking of... after a certain point money starts piling up all at once. During the first 3/4 of the game you're poor as dirt, and then during the last 1/4 of the game you've got a minimum of 10k gold unless you specifically buy EVERY skill, period.
-What the hell were the developers doing switching from a fantasy RPG to a ♥♥♥♥ing Pirate RPG?
-There's no real feeling of your character's growth - you just buy new gear and more skills every now and then when you can afford them. You don't get that feeling of "Holy crap these enemies used to be so tough but now I'm oneshotting them! I'm so badass!" it's more like, "Ugh, these things again. It's a good thing I got this new sword so I can kick the ♥♥♥♥ out of it slightly quicker."
-There are no stats. Your health is capped at 100 with no way of increasing it. You cannot increase your character's strength as a fighter, you can only increase your base "Blade" ability and then beyond that buy more blade-related skills. You choose from slashing, piercing, and thrown weapons (sabre, rapier, and spear/throwing daggers, respectively), and pistols, muskets, and shotguns.
Magic was completely removed in favor of Voodoo; which, yeah, it fits the whole "Pirates of the Carribbean" thing they've got going here, but it's still pretty dumb - especially how they wrote it off as "The Inquisition (who, by the way, you joined up with between games regardless of which faction you sided with in the first game) banished all mages because they didn't stop the Inquisition from ♥♥♥♥ing up in the first game."
The story and world are interesting.
It's fairly lengthy. Not as long as the previous game, but not short as 90% of AAA titles out there.
Some other things which I honestly can't describe (see below).
Now, all that being said I actually have to recommend this game, just not at full price. Wait 'til it's on sale, or better yet wait 'til the collection is on sale and you can get the first and second game for just shy of $10 like I did. I don't know what it is about this game and its predecessor, but the things they do right they do EXTREMELY right; it's just that the things they do wrong they do really, really, REALLY wrong, so it averages out into a decently albeit mediocre game.
...seriously though who the hell changes themes like that? That'd be like if the next Elder Scrolls game was about pirates, or if the next CoD was about Vietnam war protests, or if Half Life 3 ended up being a third person fantasy RPG like the first Risen.