Fusion Fall gives you your first 4 levels free and you can get a pretty good grasp of the gameplay from that, so don't just take MMORPG's word for it, give it a shot. It might prove to be a fun distraction from grinding xp or running that mission yet again because you still haven't been lucky on a loot roll.
A group of dedicated fans is reviving the Cartoon Network MMO FusionFall. The dev team recently released a limited early-access test build
Wow, I had a little eddy sprite during the original fusion fall. I'm glad to see it back
MMOHut, "Traditionally, browser based MMORPGs were either text based or built using Adobe Flash or Shockwave. There are dozens of high quality browser games like RuneScape that utilize these methods, and they are still popular options. But a new platform for creating browser games has emerged. It offers developers a powerful and highly versatile all-in-one tool. That tool is Unity.."
MMOHut, "Browser games have traditionally been thought of as second-rate options for gamers who don’t have the computer hardware to handle more desirable client MMORPGs. For the most part, this stereotype has been true. Browser games consisted of text and images, and it took a whole lot of imagination to make something happen with those..."