In Diablo III is a good hack n slash game but with a poorly designed loot and level system.
Number 1: The Loot Limit
Once you hit lvl 60 the items doesnt get any better. Every one tries to find that super loot but with the limitation of the low item level, the chance to get that perfect item with the perfect stats is insanely difficult. And if you find that perfect item its not much better than the one you already have.
Number 2: The Auction House
Once you hit level 60 all you need to do is to go in to Auction House and buy any item without any limit except money. You have reached the maximum item limit and can now equip items that are 10 times better than any item you could ever dream of finding by slaying monsters in the game. This makes the loot finding absolute pointless and the whole purpose of the game quickly becomes about money. Money to buy slightly better loot at the Auction House. So much for feeling special about finding unique items, big deal! People can buy better gear so whats the point?
That brings me to another problem. Diablo III:s level system is extremely dumbed down. Every person that ever plays this game has the exact same skills. So it is ONLY the items that matters. The items is your character, not you, you dont have to think about selecting the best permanent skills to make your character the most powerful by taking different paths. No, Blizzard completely shut off that option. So you cant have any unique build like you could in Diablo 1 and 2.
What i do like is the random events that appears which gives us decent replayability. The downside is that every difficulty level is the exact same, the enemies gets more life and does more damage and the elites becomes minibosses. Very uninspired to only change their stats. More enemies, more elites or extra content for each difficulty level would have been a much better experience! Something that tells me that i am on a higher difficulty level.
Diablo III is fun and addictive if you play with your friends, killing monsters is what this game does best but when you reach a certain limit where you realise that no matter how much effort you put into the game trying to find unique or good items, which basically is all you ever do when you have completed all the difficulties. It feels like a waste of life. If only the Auction House didnt exist you could at least feel proud about what you have accomplished but sadly you cant. Everything can be bought so why work for no reward ey?
The bottom line is that Diablo III is not bad, but its not better than the other 2 games.