two kinds casual and hardcore, diff between them too much, this is supposed to be a pick up and play game, you could level for 40 seconds on biosphere if you wanted to, you need to set aside at least 10-15 minutes for a few runs on voleria. This is not the amount of time needed to gain xp, this is about how much attention you have to pay to play the game. It was perfectly possible to run biosphere while watching a movie, something you just cannot do with the mines and snipers and all that lugging and walking back and forth

the game has got more hardcore, PVP came in, and the time needed for the bosses got longer and longer, it wont make a diff if you play for hours at a stretch, but it does make a diff if you play for shorter bursts

not the same as those who pay for plat and dont pay for plat, there was no real need for plat till around the time miners elix came in and it was still considered "hardcore" to play without plat at least till Slouch-O was cap. those who dont pay for plat often put in a lot of time, and in a free to play game this shouldnt be all that hard to pull off. in game gear being the best was pretty fair.