Warning: this game will consume big part of your life. If you start playing it, you will keep coming back for more all the time. Before I started playing Path of Exile, my attitude towards Hack'n'Slash genre was... let's say bad. This is my first game of such genre and I am completly satisfied.
Now let's go straight to good and bad points of PoE.
-PROS:+ truly Free To Play model, there is no such thing as Pay To Win, there are microtransactions that are all about purchasing visual effects for your character and his abilities (you can also purchase more tabs in stash, but that does not impact the game),
+ developers actually care about the game and keep fixing bugs, creating new content or reworking old visual effects (I have been watching development of PoE since open beta and it constantly changes until this day, successfully becoming better),
+ new leagues and events are started on a regular basis,
+ huge amount of passive skill points which gives you enormous combinations for character developement, every build is unique (unless you begin copying others' builds which kills the fun). There are so many possibilities that you are even able to turn an archer into a melee character!
+ large variety of active skills - you want to sweep your axe? You want to cleave through enemies with your sword? Maybe you fancy raining arrows or using various kinds of magic? No problem, you can choose anything you want and upgrade your skills so they can consume less mana, become faster or fire more projectiles at once and that is not everything.
+ many armors and weapons: one handed or two handed: axes, maces, swords also daggers, claws, bows, wands and staves, items also have different stats and 4 grades: normal, magic, rare and unique, same thing applies to monsters,
+ crafting-currency trade system, it might come out to be hard to understand at first, but then you keep realising that everything has its value, there is no gold, just barter trade system,
+ this game has challenging end-game consisting of large variety of special maps that can be modified to become more rewarding and demanding at once, if you reach high level [80+] with decent items and statistics you will simply feel satisfied
+ nice, vivid and helpful community.
Unfortunately the game has some flaws that sometimes might make you rage quit or commit suicide.
-CONS:-the biggest con is desynchronisation between client and game server or simply laggs that might turn your free time you wanted to spend on relax into the festival of rage and tears. Losing 10% of experience at level 80 is pretty disappointing since it takes a bit of time to gain it, now imagine same thing happening few times in a row. Now try to imagine laggs killing you in hardcore league which means transfer of your character to normal server,
-this game becomes a bit repetitive after some time, especially before reaching end-game when you have to complete 3 acts with 3 different difficulty levels, this means doing same quests 3 times which may make you very exhausted. The other exhausting thing might be farming experience when you are underleveled. I quit this game few times before reaching level 70 and completing all the difficulty levels, however I found a solution for this problem - do not play alone, all you need is a friend on TeamSpeak!
I hope that I managed to describe this game generally, but I have to say one more thing: you will not be able to experience the game by reading others' reviews, just give it a try and you might fall in eternal love.