It's been there for 15 years so there are a lot of content, dungeons, quests, zones. Being an old game, it kept a lot of its old school mechanics from back then. The game is super grindy but there are so many things to do that it's easy to break down in smaller tasks. It's your typical old school mmo where you have to do the same action a million time to skill up.
The old quests are total trial-and-error-need-a-guide trash. You will see much better quality quests from the more recent ones. They usually are voice-acted and expand on lore.
Typical themepark combat. Actually, you can pretty much AFK the combat if you feel like it and the game will auto-select your skills as they come off cooldowns.
Oh yeah, and it's point-and-click movement.