After playing the Infinity Blade for a few weeks, it started to get a little boring and repetitious. I've heard that the sequel, Infinity Blade II, is a better game and am curious: what are the differences between Infinity Blade and Infinity Blade II?
The second one has a lot more content in it and adds a lot of replayability. It isn't just go through the same dungeon over and over until you get enough gear to beat Raidriar. The second one has a bunch of paths leading to at least 4 different bosses.
It also features plenty of new items. 3 different types of weapons (light, heavy, dual), each type having their own combos, benefits and play-styles. There are items of all categories (weapons, shields, helmets etc.) available only by finding them in the game world. Some chests also require a small, medium or large key to open. You can buy or find keys but they go up in price every-time you start a new bloodline. Usually what you get out of the chest is worth more than the cost of the key anyways.
You can find (or buy) rare treasure maps that will show you a drawn picture of the world drawn out hinting to where a secret item is hidden for you to find. There are more types of gems in this one, and you can combine 3 gems (matching or not [matching gems however will give you a greatly improved gem of the same type]) to get a new and improved one. IIRC you could collect gems in the first but combining was not available.
There are also more types of enemies who all wield the new weapon types making each enemy require a different strategy to beat them. Also the dungeon itself has some areas that are locked when you first got through it. You have to go through certain areas in order to unlock others.
One last thing. There is also an added online feature called Clash Mob. You can read about this feature here in IGN's review on it. Basically everyone who plays IE2 can participate in events to get prizes once the event reaches a certain goal. This could be something like kill so many enemies in a row or do as much damage as you can to an epic boss. Then when the total is reached all participants receive prizes.