Tibia is an mmorpg, a little bit like runescape. It's pretty pixelly, like minecraft or teraria, but it's pretty different. There's a ton of gameplay, quests, pvp, clans, and everything.
It's very fun, but sadly I don't know how to chat in it, and that's a pretty big thing in tibia.
Like Runescape (and a ton of games out there), you can pay to get premium membership.
There are four classes in the game, but you can make them all original, by getting different skills and clothes and accesories for your character.

Tibia is one of the oldest and most successful massively multiplayer online role-playing games (MMORPG) created in Europe. In an MMORPG people from all over the world meet on a virtual playground to explore areas, solve tricky riddles and undertake heroic exploits.
From tibia.com (just this paragraph, not the top one)
You can play and join now at
www.tibia.com

A lot of people have told me to NOT post all games from wikipedia. This game is really fun for me, and there's no wikipedia (there is a wikia for it though) so I decided to make one on my own. If anybody wants more information, you can check the wikia or tell me so I can put more information for you guys.