Let me start by letting you know that I was a pretty f***ing hardcore D2 player. Mostly classic, always on hardcore mode. Countless hours, restless marathons of ladder races, ladder reset heat, dropping SoJs, all the oldschool stuff. So needless to say, I was VERY sceptic towards the new Blizzard approach on the matter of how the world of Sanctuary should look - meaning the "my pony puke" kinda style, you know perfectly what I mean. Nevertheless, as an all-time fan of the series, I had to buy it and try it out.
Surprisingly enough, Diablo III is actually a pretty awesome game as it turns out. Despite a bit candy-like graphics, perhaps overdetailed UI, crap character development model, all the useable items requiring end-game level to wear and the abysmal Auction House (which now bites the dust, fortunately), this game can grow on you and grant countless hours of brainless hack'n'slash fun - and that's what we're all after here, right?

First off - the game design is under speculation for ages now and some may describe it as if a unicorn took a dump all over the place with all the colors of the rainbow. And it's true - none of the dark, depressing tone of the predecessors remained. However, if you manage to get over it - the UI, effects and models are actually well done (as you would expect from Blizzard). You may say that as far as the spells are concerned - the flashy, glowy approach may do the job, but the Barbarian could use a bit more, well, direct effects (perhaps some meat flying around, blood sprouting) - but hey, it does the job.
The thing that's much worse in my opinion, is the skill model. After creating and executing the best way to involve some kind of intellectual creativity from the player in Diablo 1 and 2, they decided that every character will possess the ability not only to reset all the skills but also that each skill is simply picked - not scaled. How do we calculate damage then? - you might ask. The answer is - DPS (damage per second). I tell you - this is absolutely brainless and it affects the gameplay in a way that noone with an IQ higher than the squirrel's would appreciate. What this means is that the higher damage your weapon has - the more destructive your attacks will be. This may sound like a logical thing, but how exactly does a massive axe relate to creating a fireball? I fail to understand.

Many things don't make sense in games and they get away with it - by making it fun. And, well, I admit that begrudgingly, but Diablo III is indeed fun.
The cinematics and the story are awesome. The plot has its downsides and generally - it is hardly anything innovative for the series, but overall, the epicness (so typical for Blizzard) is maintained.
The music suffers from the same stigma as the graphics - it is "improved" and the atmosphere has changed a bit. Nevertheless, it is still inspired by the original pieces by Matt Uelmen, but the said composer had nothing to do with Diablo III's soundtrack. The tunes are more sophisticated and detailed, I had the impression more instruments were involved and all in all it is a slightly different approach, but worry not - the "diabloness" is still there.

The base game contains 4 acts, you are able to finish the game within a day if you make the effort, but for a regular, casual player it should take less than a week.
This game is designed for multiplayer mainly and that's where it shines. Co-op games have 4 players maximum and you can join any game at your level of plot advancement or lower. The character level cap is 60 (with the Reaper of Souls expansion - 70) and past it, you keep gaining levels called Paragon - which grant you additional life, armor and other attributes, but at the level cap you possess all the skills (like fireball, blizzard, special slashes and summons) and no further improving upon them is possible.

The game includes two modes, just as in Diablo II - softcore and hardcore. the first one is a regular mode just as you would expect from a game: you play, you slay, you die. Once you do that, you respawn somewhere, loose some gold and that's it, easy peasy. Hardcore, on the other hand, has a much more exciting rule - you may die only once. After that - you're done, rewind and back to square one - all items on you, all your experience, your whole character is like it never existed. Luckily, you can still keep all your gold and the items in your stash.

Back in the days when the Auction House existed, the game looked totally different. It worked like a general auctioning service, not unlike eBay. People placed their items on sale and others could bet until the timer ran out. The option of stating a "buy now" price was also available. This, however, led to a simple series of acquiring end-game items: you either farmed the gold, flipped items (buying for cheap and selling high) or had luck with a good find and exchanged it for high amounts of gold. The last option being occasional, two others remained as regular ways to get the items you wanted by simply getting the required gold and buying the items on the AH.
This model tended to get the players away from the game and its main purpose (having fun finding items) and made them focus on Auction House trades. Many people actually got a decent amounts of real money on the Real Money Auction House (the place where you could buy and sell for real $, allowed only on softcore). Eventually, in 2014 Blizzard shut down Auction House and now to get an item - you gotta get it dropped. Each item is bound to the account that got it dropped and you may only trade an item with another player if
- he was in the game when the item got dropped,
- a 1:30h timer hasn't run out.
This is a rather harsh model if you ask me, but with loot 2.0 as they call it - items that drop take into account what character class you are playing so the chance that you get an item totally unfit for your character is unlikely.

To sum this lengthy review up - if you haven't tried Diablo III, I strongly recommend you take on the single-player campain at least for the epic cutscenes, fine plot and addictive gameplay. To those of you who enjoy multiplayer, find yourself a guild because right now the game is deserted considering public games.