Random enemies: Enemies other than bosses and shard lords are random.
Random enemy weapons: Human enemies can have any weapon in game randomly, including guns and the red katana.
No random pursuer: Pursuer only spawns on levels it has to.
Instant pursuer: Pursuer spawns as soon as the level starts.
Random drops: Enemies can drop way more or way less loot, and normal ones can rarely drop shards.