Tibia for me is considered a mix of retro gaming with modern gaming, it is retro because it is a game launched in 1997, it is modern because it is still updated to this day.
In my opinion the game graphics is REALLY inspired by Ultima games, specially Ultima VI
Here some screenshots
Modern version



Old school version


The creators wanted to create a online dungeon simulator like those present on BBS,but with a graphic representation to improve the immersion, then Tibia was born,it is Free,however like any other MMORPG it has premium feature that you enable by paying a monthly fee.
Recently i'm back to Tibia and man, those memories, back in the day(about 2005) i didn't had any money and the game was way to hard for me so i made my OT Server(OT means OpenTibia, which is a open source server of the game), and made it 10x so it was way easier for me and eventually people joined, my cousins only played the official servers, and when i went to their home i experienced the twitch of the 2000's, sitting on a chair watching they play, i had fun though.
But what about you guys? someone still plays or played back in the day?