You can play ArcheAge for free online, if you download and install it. It is both a “theme park” and/or a “sand box” live single and/or multiplayer game. You will learn and/or risk experiencing and/or enjoying “being lost” in a virtual world, where you may build/conquer/craft/solo/team. Sweet!
You can also watch SwordArtOnline, if you have a NetFlix (not free) account, and watch the episodes. What would happen if you signed up for an online single and/or multiplayer game that you could not log out from and if your physical life depended on your virtual survival?
Both virtual worlds I find worth watching:
. ArcheAge requires frequent computer interaction
. SAO requires minimal computer interaction
Either way, may you choose how you play and continue!