As Cat says it's a great game, but play on a private server.
I, and about 3 or 4 friends had a great time when it first came out to about the time of the first expansion, right up until they removed tagging for damage/kills (so you could no longer see who had been attacking your base and killing your pets), which led to massive nonsense, then they opened it up to cross server/region travel which combined with some duping bugs and an invasion of Chinese players killed it for us.
We could cope with having our base blown up and robbed blind without knowing who had done it, we could almost cope with it happening a second time except all our pets were killed, then just as we were getting back on our feet for about the 5th time in 12 weeks the cross server invasions began and we gave up because hundreds of hours of play could be lost in a matter of an hour or two and even the "big" clans on a server couldn't do much when an organised server invasion started with people whose only intention was to level everything they could find.
We considered starting over on a private server but just didn't have the energy and were burnt out by the dev team seeming to be made up of idiots who'd never played an mmorpg before, or realised what happens when you make it impossible for people to find out who was doing stuff (so no chance to self police a server*), or put anything safe when they log out.
We didn't mind losing stuff too much, but logging in every day or so to find everything destroyed and you left naked again with nothing but xp/skills is something most games seemed to realise was not conductive to long term play (as you can't put 4-8 hours solid in every day just to get a hut and a couple of animals).
As I say, great game in theory, shame the devs didn't learn anything from 20 odd years of other MMORPG type games when it came to how people behave with no checks/balances in place.
*When stuff was logged when destroyed/killed it meant clans on servers could work together to defend each other/deal with griefers etc.