Endless mystery dungeon

In this world in which it is that of stats and Mana points like a JRPG, outside of the villages and cities lies a massive castle in the mountains which below this castle lies an infinite realm of infinite floors of environments of any kind from dense jungles to mountains to even ice caves. This realm has been dubbed “the mystery dungeon”. There are four races, humans, elves, rabbit-kin, and halflings. Humans have higher attack stats, elves have higher mana stats, rabbit-kin have higher speed stats, and Halflings have higher defense stats. There are six classes. Knight, mage, gunner, shield-user, seer, and thief. Knights use swords and shields, mages cast magic, gunners use revolvers, shield-users use shields as blunt weapons, seers use needles, and thieves use daggers. You, your soul has been cast into a world of adventure and possibilities where you could become a great hero. You have descended into the mystery dungeon as a new hero.