The mobs need to spawn more randomly and be different assortments of enemies. The same mobs, with mostly the same enemy types with endlessly spawn in the same areas. The "get 9000 XP without dying" challenge was sort of a joke. I'd assume this will change in the final game, and I really hope this game doesn't turn into another GTA online, with the same missions being farmed for challenges, money, and vanguard points. It could get really boring, really quick if that's the case.