Bots
Simple MMO.
You choose from one of three 'bot' machines to control. Then go through little missions for gigas(form of currency) and xp to level up.
One cool thing about it is that being higher level doesn't make you stronger, only allows you to wield stronger parts and gear for you bot. I have beaten others who are 10+ lvls above me in pvp.
Drawbacks are the chat system and the special items. The chat in both the lobby and during missions is limited to so many characters. And getting anything past the regular upgrade items costs real money. You can get items with bonuses on them(ranging from +1 to +5) which are gotten after a boss is defeated, but they only drop rarely, and if you are playing in a big group then it's a mad rush for the box.
Still, a fun game I play every other day, quick to learn, easy to play.