I think Sudden Death itself is the wrong approach. I don't think it changes much objective wise... both teams still have to destroy each other's base , only they can't rebuild some buildings or upgrade.
As I said , Tremulous suffers from critical game flow obstruction. Since territory control is rarely rewarding , defending the base until the enemy is significantly weaker is the best strategy. Attrition of defenders is impossible , since buildings are free to rebuild ; while each attacker dying helps the other team.
The game would have more meaning if team goals were asymetrical , and the time limit would automatically make one of them win. It could be either human survival (fort alamo gameplay) , or eradication of aliens (infestation hunting gameplay) , then team attributes and resource models could be adjusted accordingly.
NS Combat is a good example of this - humans have to kill the alien hive before the time limit , so they need to move out of their base to win , but aliens may counterattack and win by destroying their command center.
