So, where did it go wrong?
1. The story was adapted from the films and it'd not have been a bad adaption necessarily except for the fact two thirds of the game is set in the second film. Yes, you heard right - a film based on the third movie, or at least named after it, features mostly second movie story and locations. Quite bizarre. The production company had commented in an interview how they'd had really good access to all things PotC but it makes me wonder if they didn't get enough access to plot for the 3rd film incase of leaks. Either way it was a terrible move to have maybe a third of the game actually involve what you'd expect from the title. I'm not sure what the Dead Man's Chest game can be like since half of that films material was used here.
2. The controls were not the easiest to use, and when you do get them you find out there's little variety. Having played Heavenly Sword I found myself wishing the knife throwing at least would have some kind of aiming with six axis to make it more skilled but it ended up just button mashing and unsatisfying.
3. Sword fights of the staged variety, as opposed to the button mashing mostly employed, had nice humour that you could relate to Jack - who you are usually playing and is never seen outright killing during these stages - but the controls for them were hideously sensitive on both the timing and flick of the analogue stick meaning you could go from doing pretty well to dead with a few moves that you'd got a tiny fraction out on. Given the last boss fight is using this style of fighting that'd be one of the reasons replaying the game would be an act of torture.
4. It didn't feature particularly good voice acting, in some cases the voices for the characters were completely mismatched. The best voice was for Jack, then Barbaross and Governor Swann, though often enough even they came across sounding a bit Australian to me. Norrington's voice was somewhat different to the films but at least still in character and hence not too far away from the original actor to be a big issue. Will's voice was entirely too gruff and unlike him, as well as badly delivered in my opinion, plus Elizabeth seemed conversely very bitter or almost girlish with little in between or inflections of other moods. I expected better for such a well known franchise.
Apart from those main faults there was a general feeling the game had had some good ideas but ended up as a mashed together thing as films>games titles often are. The chests with items strewn throughout levels were totally in character but left me feeling they'd copied the earlier Harry Potter games then crossed with Tomb Raider.
Another area it was lacking in was originality. What little was to be found was nice but not enough to make the game stand up on it's own right. I think I was particularly disappointed because the game could have been so much more quite easily. You could curse the lack of development time or it could just be producers not trying as hard as they should, either way it's not a game I'd recommend to buy but some people may enjoy it as a rental and it may well be much more enjoyable on the Wii, hoping the controls for that are better.