I read all the ideas and if I had to choose one, Shift would be it. I can't come up with a better one myself. It seems to nicely combine all the aspects of the game you have mentioned and it is one strong word. When choosing a name, you need to think of the logo and how it will look. It is way easier to design strong logo with one word than with more words.

Example - Blizzard has Diablo, StarCraft, Warcraft - three strong, one-word titles. WoW is still basing on the Warcraft logo, exposing Warcraft the most, cause Warcraft was a stronger brand when the logo got designed. If they weren't using an already well-known IP for their MMO, I can assure you, they would choose a one-worder.

Well, if everything is so toss-up, why not stick close to the base?

It's a sandbox kind of experience?

"Starbox".

Not only is it familiar when considering game-types, but it's just one letter shy of a multi-million dollar franchise without getting anywhere close to Nintendo's game design.