My first thought, having seen the original in the theater, is that this is the same type of movie that my generation grew up with. Monsters, a hero, a heroine and all the "good stuff" that we used to watch on Saturday mornings or (if you grew up in the tri-state area of N.Y., N.J. and Ct.) the 4:30 movie.
Clash of the Titans sort of "is what it is". It is the stuff of young kids' adventure fantasies and as such has to be judged on that merit.
So, having said that, and having seen this remake, this "could" have been great. Bob is correct in that there just isn't much for us to grab on to as far as us caring for the characters.
And some of the characters do indeed feel added on. For no reason.Calibos does feel tacked on and the djinn sorcerer also feels tacked on. Calibos shouldn't have been handled this way as he is actually important in the first movie. There is a sort of comedic duo of fighters who also come along but who also feel tacked on.
Io is also tacked on but gemma arterton is just so damn beautiful (in my opinion) that I didn't mind. However, because of her inclusion Andromeda sort of suffers a back seat.
This movie suffers from writers who made changes for no reason whatsoever. And to add insult to injury we don't see why humanity is pissed at the gods. We are "told" that they are. It isn't until a bit into the film we get to see why Perseus has an axe to grind.
It's as if they forgot to include or develop proper motivation and purpose for most of the characters.
So, in the end I enjoyed the film because I brought my 13 year old self and had a blast. But my 42 year old self couldn't help but think that the movie needed to be tightened up a bit, remove Liam Neeson's bad armor, actually include Poseidon in some of it (as my girlfriend said, he seems important to the whole thing yet he really is never mentioned except for the start). Also there was no need to use Hades as they did.
If you like fun monster movies go see it in 2d. If you are looking for incredible writing, mythology that makes sense and great movie composition then don't bother because you will be disappointed.