Basically, clear all regular classes and gender variants in one sitting to unlock novice, then the run ends when both novice gender variants clear Prontera Castle, the secret 9th stage.

Since it only says beating all stages with all classes to unlock novice, and then using novices to clear all stages, I wonder if two-players will speed up the unlocking process in general.

But then again, seeing as all regular clears seem to be around 1hr:30min, doing this all in one sitting is going to be horribly exhausting.

[[Unlockables: https://rbo.fandom.com/wiki/Unlockables ]]

Novice Class Beat Stages 1-8 with all Classes (6 Classes in any gender) to unlock Novice male and female.

Stage 9 Beat stages 1-8 with a Novice to unlock Stage 9. This is the last stage before the Ex stages.

Secret Stage There is a secret 9th level in Prontera City which is unlocked if all previous eight levels have been beaten with the Novice class.

* Prontera Castle
  Boss Monsters: 100 BOT and 1 BOT with aura

Hypothetically, if two-players could indeed speed up the novice unlocking process, then we can see interesting class combinations. Maybe have an archer+swordsman duo in a stage where swordsman struggle, or thief+mage where mage struggles, etc.

There is however a big problem. Each time you clear Stage 8 Prontera city and beat the Kafra, the credits will play and this is going to be a gigantic time loss.