To explain further on ArcheAge, you basically quest to level (you can level via crafting/farming as well, but its slower), you can do dungeons and you have tabtarget combat - think of it as WoW. That's why it's part themepark. Now the sandbox parts you have: open world pvp, non-instanced housing / player plots, farming, growing trees, player driven economy, goods trading, castle sieges, naval warfare and pirating, underwater treasure hunting, sailing, castle building, fishing and more.