Its leveling system was really dope because it was sci-fi based. Anytime you made a major class decision, you got a clone of your character to try out the different branches that were available to you after your upgrade. So like everyone starts out as the same base class but then you can branch off depending on your skill choices. Like say you wanted to do AoE tanking and you didn't like it you could switch to a different style of tank with your clone.
Also, the PvE was really awesome. It was set in a war zone where you're fighting against an evil alien coalition, of course, that you would have to fight over control for bases on. So there were some dedicated human bases that could never be taken over, but if you happen to log out in one of these bases that you fought for control over, you could log out and log in, in the middle of enemy territory if the base had been taken over.
That aside, Minecraft still gets its hooks into me.
Literally, a mining game 😂