It's also a correlation between these factors.
- Personal Progress; How fast your hero progresses in terms of power, this includes items. This is measured in relation to your teammates. Nobody enjoys when one person gets an object of immense power and gets to do everything, and not many people enjoy games where leveling is a slow crawl.
- Quality; Sadly, most RPGs are **** these days, and there isn't much (or any) testing done. There are still some quality ones out there, however.
- Length; Big one, if you look at RPGs these days, they're getting shorter and shorter. I have to keep believing groups like Bioware will stop cocking up the length and actually make an RPG for RPG lovers.
- Concept; I suppose this falls into quality, but it has to be it's own category these days. People tend to be drawn towards common media as usual, so Anime RPGs tend to be more popular than not these days.
Also; What the **** is with all these life simulators that make you do the most tedious ****, ever? I should probably sit down one of these days and make an RPG that isn't absolute ****. Just you, a hero, and ass kicking from point A to point B.
:EDIT: Swear filter? Grand. Insert your own swear words, please.