Its ironical that as we see sun is setting on MMOs , the one game that is not actual MMO is everything people wanted from that pie in the sky sandbox MMO.
The real move forward came from totally different ( and new ) genre - survival games.
And let review the features :
1. Completely Skill based freeform - You gain EXP by doing things , you invest skills into completely freeform system. You can specialize or be jack of all trades. But nobody can be 100% self sufficient and at the point will need to rely on others.
2. Levels are not very important - A fresh player can equip highest level equipment and be deadly , and vice versa
3. Build , craft - You can build anything from a sleeping bag to city . From axe to self sufficient electronic powered eko zone. And you need , in order to survive.
4. You influence environment - You can clear forests , kill wildlife , tame , corner , set one on other - Its a living world and your presence changes it.
5. Your influence politics - Just like in EVE for that mater. Everyone is on the same island, there is no limit to interactions good or bad. You can raid , burn , pillage , kill , imprison , take hostages , sabotage , steal ... or trade , enter aliances , help ....
6. Grind - There is always some goal , something to strive for. Pehaps to tame some new species , or to strive towards building something... and all this needs lot and lot of effort and time.
7. Constant danger - You are never ever safe. From other players , wildlife , thirst , hunger , cold - You must always be on your feet. No dull moment.
8. Exploration - Fully open world with forests , swamps , caves , snow peeks - no invisible walls
9. Endgame with no endgame - Aside for mystery of island , its pillars , you have very high encounters - but only your imagination is the limit. What will you be ?
10. Its not DayZ. This is actual game with actual content, that is added almost every week. Not empty shell with nothing to do than kill newbies.
Here people MUST work together to actually accomplish something in game.
11. Hardcore but not hardcore - You lose everything you own on death. But you never lose your character progress.
We have a game that has all ingredients of dream sandbox MMO. But its actually game limited to 70 people per server.
And that is only thing that makes it non MMO.
What an irony