-Lets start off with the big one: there is absolutely NO sense of continuous play to the game. Don't get me wrong, the storyline was fine, I enjoyed it, but once you get to level 60... Honestly there's nothing left to do. Spend a few days attempting to beat inferno, and if you succeed, there literally is nothing left to do, except spends hours playing through a storyline you've played through hundreds of times over n over attempting to magic find. Having such a low level cap, ruined the continuous play aspect to the game, instead of how d2 was, it took a VERY long time to reach max level, giving players a thrive to keep playing their character. One week into the game, and I'm already bored out of my mind.
-itemization is complete rubbish, for three reasons:
1) there is no sense of direction with the items... magic items being better then legendaries and sets, it almost seems pointless to get magic find items or even get a thrill if/when a legendary drops, because you know your equipped magic item will be better.
2)Even if legendaries or sets were any decent, drop chance of them is WAY too low, I personally have cleared 3 whole difficulties, and half of act 1 in inferno, and have yet to see either a set or legendary item drop. This takes away the thrill of playing a gear dependent fast paced adventuring hack and slash, makes this aspect of the game boring. I remember in d2, you would see at least 2 or 3 uniques drop per act, even with no MF at all.
3) Horrible, and i repeat, HORRIBLE item stat structure. I wonder if blizzard even spent any time at all coming up with these items and the stats they have, honestly it's so dull, boring, and tedious. One example is weapons; the only thing that really matters is the dps, and nothing else, and since melees and casters use the same damage formula... it's complete linear and boring. You see wizards wielding these incredibly high dps weapons, instead of how d2 was where there was honestly 10x more different stat structures, and a magic class would be completely different from a melee class. Melees and range classes also use the exact same armor, again, boring and tedious... everything's the same.
-There is absolutely no social aspect to this game at all... 90% of the players currently are either just solo-playing through it, or playing with a group of friends. No more chat rooms, no more server list, (the current public game setup is a complete joke...), it makes the game unbearably boring after your first run through. What ever happened to the huge social style of game play that D2 had? It made the game incredibly fun.
-Game is way to linear. Every play through, the map is the EXACT same, disregarding a few little random dungeons they may have a different layout. What the hell was the point of this?... I thought maps were suppose to be randomly generated? The new progression system also makes the game even more of a complete bore, instead of opening your game and being able to freely go anywhere you choose like in d2, you're stuck picking a certain quest and being forced to go from there, WHY?! who ever thought of this idea, you good sir, failed.
-classes being WAY too imbalanced. Long story short, melee classes get absolutely pooped on in inferno, and there's nothing we can do about it, while range classes at least have a chance to succeed, even in inferior gear. We know inferno was ment to be extremely hard, but seriously, there's a difference between hard, and impossible (referring to melees). Good news? At least this issue can actually be resolved unlike some of the others.
-Forced roles (again, coming from a melee standpoint, and referring to inferno). We're tanks, kiters, and buffers. That's it. We have no choice in the matter, and it stinks. Worse part is, we can't even be a hybrid, cuz we have to load our passives and active skills with all tanky-type skills, or we die, leaving no room for any of our cool, fun, offensive abilities. Worse part is, with the new layout if the skill system, and only having a max of 6 skills able to use (which we mostly have to have tank skills there), we can't even use our other abilities they normally would increase the fun in playing. Personally, i found d2's setup much better, at least i wasn't forced to only use certain spells, and i could actually use all my abilities at any given time.
All these flaws combined, along with the others i haven't made a paragraph about, such as elite/rare mobs being harder then 2, even 3 act bosses combined,or the fact mercenaries being complete rubbish compared to d2, will make this game go down in ashes. Yes, the first play through was extremely fun, but there is no sense of continuous play, at all. People will get bored, and fast.
Something i found ironic, is a long time ago i remember reading a blue post, that a blizzard employee stated they didn't wanna create a replica of d2, but a whole new exciting game, but you see, that's where you're wrong, if you're going to make a "whole new exciting game", at least move forwards, not backwards, otherwise you should have created a replica of d2, just with a new storyline and new features. Why? Because it worked.