I recently started playing this insanely dumb, weird MMO game made by Cartoon Network, of all people back in the 2000s when everyone and their Dogs were making them. It's called FusionFall and it's pretty fun! It was shut down in 2013, but some people revived it as "Retrobution".
You can download the game here: https://github.com/JadeShrineMaiden/OpenFusion/releases/download/1.3.5/Retrobution-1.3.5.zip. I'm "Ben the RoboNerd" ingame.