First of all - I'm not saying it was the first MMORPG ever, since I know there were several others. Many people don't even consider Runescape a MMORPG nowadays, since it's said to lack roleplay. Anyway, Runescape launched on 4th January 2001, and on 21st January there were already 28000 registered members. For 2001 that was a very huge number of users. The game was called Runescape Classic back then and there graphics were... ummm... not the best. I can't really tell of my own experience with Runescape Classic, since I registered in the end of 2002, and barely played it back then (most likely because of my near-zero knowledge of English, lol). Even back then the game offered many hours of gameplay and the most important aspect throughout the history of Runescape - pking (player-killing). Oh, how fun it was to compete with other players in Wilderness, the dangerous zone, where other people could attack you. If you died anywhere - you lost everything you had on you, except for 3 most-valued items.
When Runescape 2 came out in 2004, the graphics improved. The mechanics of the game became better and more complicated. Emotes were added. Bank was made more player-friendly. Basically everything became easier to use. Until 2007, the game was constantly improving. New quests (the missions in Runescape) were added very oftem, and hundreds of new items were released. There were also the discontinued tradable items - they were available to get on a certain holiday in 2001 and 2002, and since there were no new ones coming out, their value rose to millions. In December 2007, all the fun things came to an end - Wilderness was removed because of Real World Trading problems, duels (safe way of competing, while it was possible to stake items/money) became restricted for the same reason, and a trade limit of 3000 loss/profit was set in place. Real world trading got a huge blow, as did bots.
The economy became absolutely controlled and scamming was made extremely hard. Many people quit and there were many riots for the first few months all of the Runescape world. Nothing changed though, and everything became as it was only on 1st February 2011. Seemingly a good change, but it ruined everything. Bots returned in such amounts as if they were compensating for the lost years. Discontinued items started costing billions etc. Overall - real world trading got to it's peak.
Enough of history now. About Runescape itself. The game offers THOUSANDS of hours of gameplay and there's always something new to do. Many items to create, hundreds of quests to complete, raise any of the current 25 skills, and so on. Or the most important aspect once again - killing other players. Some of them do have honour, some don't. Some act mature, most act childish and insult you on the first possible occasion. That is probably the reason why many consider it a childish game. Thoughout many years JaGeX, the creators of Runescape, have made it more and more safe, and more player-friendly. All the new colourful buttons seriously leave the feeling of childishness nowadays.
I'd give Runescape a score of 7.5 for the good years that I had playing it. Not for the game that it is today, no. I loved the pre - 2008 times and they will never return. The 2008 (was it then?) graphics update made the game look more beautiful, but also more demanding. The amount of things to do and the huge world contribute a big amount to the score I give Runescape.