For better or for worse, I have a soft spot for collaborative online RP games. My preference is “freeform” roleplay, as opposed to rule-based roleplay. In a typical rule-based game, when the zombie cow lunges at you with an infernal moo, you roll a die to see what happens to your character; in a freeform RP, you declare what happens, ideally by balancing common sense and demands of drama (or, more commonly, your character conveniently dodges all attacks until the GM starts looking at you askance.)