Well since I'm watching and seen the game I'll give a you brief overview.
The anime basically follows the game so I'll just tell you how the game works.
Basically you start out as a novice. The entire game is like wack a mole, wack, gets points, get points, get exp, get exp level up. When you reach level 9 job, you can change into 1st class..which consits of Swordsman, Acolyte, Mage, Thief, Archer, and Merchant. So now the process repeats all over again, the higher your base exp is, the better weapons you can use , stronger monsters you can kill, more exp. to level you faster.
Once you reach level 40, you can change to 2nd class. Or now they have 2-2 classes. You can only change into depending what your 1st class is so...
Swordsman -> Knight or Crusader
Thief -> Assassin or Rogue
Archer -> Hunter or Bard (male)/Dancer (female)
Acolyte -> Priest or Monk
MAge -> Wizard or Sage
Merchant -> Blacksmith or Alchemist
So then basically you do...the same thing (does this game give you a hint of why I quit?) all over. The highest job level you can get is level 50, the higher base levle you can get is 99. Or you can just not change at all and be a super novice, I know KRO is giving special features to those who wanna be novices forever, but that's really for people who have no lives and play 24.7.
In the anime its the same thing, except they try to make stories and give the "monsters" feelings, which when you play the game doesn't happen. The one difference between IRO and KRO is most people in KRO play in groups, because asia is a collectivist culture, while most people in America are individualists who get greedy and play on their own/bot etc etc...so the original idea of the game to "play together as a team in a guild etc" is kinda lost in the American version.
Anyway good luck with your interview!