I've tweaked my implementation some to make it more conducive to non-automated play. The experience needed to level is significantly lower after level 10 or so than in the original.

Also in my implementation rather than play as the original races / classes you play as Angels or Demons which can possess and play as monsters/npcs to experience different play styles without having to create new characters.

The Angel class is the default for new players and has a mechanism by which experience points are redistributed periodically from players with more to players with less which helps newer / less active players catch up / stay relevant. Veteran / active players who get tired of carrying the team can go dark side and become demons.