Ill-conceived design mechanics make a potentially decent game much less.
Of course the first comparison which comes to mind will be Dynasty Warriors, and its really not too far off. You have a basic, chainable primary attack, a ranged attack as well as some interchangeable skills to choose from and items. The potential of this system isn't bad, since it HAS worked in other games (I personally like DW games and other similar ones), but it just doesn't come together here.
There is no blocking in CoD and any sort of evasive maneuvers are limited to a few equipped skills, so you're basically pressing the attack 100% of the time. This wouldn't necessarily be bad if they had succeeded at making attacking feel satisfying and fun but it just isn't. Your combos are repetitive and despite usually having two different weapons equipped, completely linear. Skills seem vastly under-powered and just typically lack any kind of "oomph" to make using them engaging. Once you get over how cool it looks to slash through a knot of enemies in High-Def (and it does, admittedly), the appeal of this game's combat becomes pretty much nihil.
Also with the skills, learning them can be an incredibly arduous and repetitive task. A number of them require you to do something as asinine as repeating the opening section of the game (or the first 4 sections of it, more appropriately) a number of times to meet a quota towards learning the skill.
Why? There is absolutely no point to this but mindless repetition. The enemies don't increase in difficulty, the drops don't get better and by the time you've leveled a bit the only challenge is to your patience in having to walk all the way back through the zones again. All that to gain skills which are next to useless in the first place.
The presentation and graphics of this game are great, and besides the stunted combat system itself, it actually plays pretty well. The character development and inventory/loot system is actually pretty nice as too, offering a bit more depth than most games of this type. You can even play co-op online, which is always a plus in my book.
What it unfortunately comes down to though is that the game is just a lot of monotonous grind, without a lot of engagement or payoff. It's not "bad", but the game mechanics just render it horribly, horribly boring. Its nice enough to look at that you could probably soldier through it at least once but pretty graphics are an asset to good game, not a saving grace for a sub-par one.