K’aresh is very monotonous in all aspects, gameplay, story and aesthetics. It was a chore for me to play through and I still havent finished those damn eco dome quests.
Undermine was the peak of TWW for me. It had lots of neat places to explore, it had the drive system which made getting around fun, it had a lot of different things going on and the Cartels all felt just a little unique in the quests they offered.