Like watching grass grow in a high security prison yard.
A game of EVEs size would take numerous pages to go into the depth required to fully explain its mechanics and function. However, reviews are for people trying to decide whether to buy the game so I'll keep it to the main points.
First of all, the game captures immersion literally like no other game. You ARE a space captain in every sense of the word. If your character dies, he's dead. Hope you have a high quality clone nearby to absorb your lifelong acquisition of skills or say goodbye to the months or sometimes years of training your character had. If your ship gets destroyed, you don't get to respawn. Hope your insurance policy is up-to-date because you don't get another one.
That's the overarching problem with EVE. Its real life in space. Real life is boring, that's why we play video games. Much like a space captain your daily routine is "go to work" then "go home". Occasionally you might have some costly fun in WARDECs, low/no security space, or something similar, but its pretty much, get up, go mine/rat, go home. Anyone who says mining and ratting is fun would die of a heart attack within mere minutes of playing something like Mass Effect 2, the excitement would literally kill them. You have bills too. You have to keep your insurance policy paid for your ships, you need to pay to keep a scaling clone for your skills, you need to pay for every bit of ammo you use, unless you use laser weapons which are so godawful at everything they do you'd have to be a masochist to use them (I played in an Amarr Battlecruiser for 2 weeks don't argue with me, I know what I'm talking about).
The difference between EVE and real life, aside from being in space, is that in real life you can call the cops. In EVE if someone waits at a low-sec warp gate with warp jammers for the sole purpose of destroying the ship you've just spent the past month getting the cash to pay for, you can only put a bounty on them. You know what happens if they find out a bounty is on them? The suicide with an alt account and collect the bounty on themselves using a clone to still make up the difference, laughing all the way to the bank. You have people sitting in dock in high sec space running scams like false advertising special versions of ships unless you very carefully read the fine print trying to cheat you out of money. Can you report them to the cops for scamming? Nope, this is outer space buddy, no one can hear you QQ. What about a multi-year vet multi-boxing 4 accounts with Tier 3 battlecruisers? These guys are fun, they'll declare war on your small corporation then fly around high security space killing your members until you pay them their multi-million ISK blackmail fee.
Basically, EVE is an amalgamation of the worst things about real life. If you're the lowest common denominator in real life, you'll absolutely love it. Its basically a libertarian's wet dream, and if you weren't convinced libertarianism didn't work as a political system before, there'll be no doubt after playing EVE.
The technical stuff is basic. Combat is lock on and shoot til the guy is dead or you are. Totally automated. Mining is also automated. Lots of running back to port. There's no structured endgame, and the PvE boils down to ratting(killing mobs and harvesting their bodies). The skill up system takes years. No really, years real time. There's no EXP system, its just about how fast your character can automatically read every text in existence about the topics (Electricity, Shielding, etc). You have about 6 months real time of just sitting in port before you can start hanging with the big boys, no matter how many hours a day you devote to it. Real-money-trade is legal, there's even a guide on the official website of how to do it without violating the TOS.
If you like an experience where you log in to something as close to the real world in space, with more violence, then EVE offers you a level of immersion in a digital world unprecedented in gaming. Don't complain when it acts like the real world though, and rains on your parade just because it can.