This game has everything Blizzard shines in. Great music, amazing graphics, awesome cinematic, and even fantastic voice over. The gameplay is quite fantastic.
However, game mechanics leaves much to be desired. The amount of character power is limited, with much of ones damage coming from legendary items instead of the character themselves. The dev team has attempted to combine the showering of loot in Diablo3 with Legendaries, and the rarity and item chasing loot of Diablo2 with Uniques. Alas, the outcome just resulted in ignoring most of these hard to find uniques, not even using the dropped legendaries, and just farming good rare items to affix legendary powers on to.
Itemization is obnoxious. The game falls into the same trap that Anthem (By BioWare) did - too many sub-stats. This just convoluted the game, and ended up making specific skills required due to how damage is calculated - resulting in being forced to take specific skills (ie. Sorc Frost Nova for Vulnerability - horrible stat anyhow, and functions as a second critical stat, making is a must need since it can also CRIT).
Game launched exactly like Diablo3, and needs a loot 2.0 update already.