On the original game the level cap was lower, also you got into Epic and Legendary with much less levels and less stats. Titan Quest has a big legacy of items and item affixes, that were tuned for the original game. The game balance done mostly by buffing underperforming features, and in rare occasions some light nerfs. The main focus is the items, core to the ARPG experience, but also contains several system adjustments and lots of (bug)fixes. The mod is mainly about balancing some aspects of the game, with special care to not break the original vision of the game.