Lets see, you guys want some old school stuff? Lemme think. I played Cats since it first came up, until about a year ago.
No all names.
Hiding inside the shadow of another player, so a monster couldnt see you.
No lockdown limit.
Placing houses on uneven terrain on top of books.
The ore bug where you smelt from trade window. I cleaned up on that one.
Nightmares running through house doors.
Mib's without serpents.
No arrows to controll your skills. Walk past a campfire, gain camping without a choice and lose your gm.
No controll slot's. Could have as many drags as you wanted, but they would get out of control and turn on you.
Mystic llama herder's. Which I ran into. He changed from human into a purple llama that sounded and hit like a dragon.
Server wars.
Recalling while red.
Perma-grey.
The vendor buy, where you changed the price of your items at the last minute and got mega bucks from players, lol.
The black hole duping bug. A bug in which OSI's economy still hasnt recovered from.
Could switch back and forth from chaos/order immediatly.
Swordsmanship was the bomb. And halberds owned.
When you didnt get the t2a version, people who rode llama's looked like they were riding nothing.
The origonal chest type loging screen.
And thats it for now, im to tired to think of anymore, hehe.