So it has become apparent to me that everyone hates it when humans camp. I've come up with a couple quick ways to solve this as well as add interesting elements to the game.
Suggestion 1: A purely area of effect suicide alien
This alien, similar to the baneling in Starcraft, is controlled by the alien hivemind and has no remorse for human life along with its own. Upon activation, this unit will self-destruct dealing massive damage to surrounding humans and structures but the alien player will get no evolution points from this. This alien will be unlocked at the same time Dragoon is unlocked and will end the human camp fest, permanently. A low amount of hitpoints combined with low movement speed -similar to that of the Granger- makes this alien only capable of one thing; suicide missions.
Suggestion 2: Power/Creep win
Both teams will have the ability to build structures that increase creep/power range. These structures could simply be eggs and repeaters, but they could also be unique buildings that are free to build (what I would suggest). Once a team has covered a certain percentage of the map in creep or power they have met a victory condition and a warning is displayed on the losing team's screen with the message, "Humans/Aliens control too much of the map! Push out or we will have to fight another day/retreat back to the hivemind." They are then prompted with a 2 minute timer that counts down to the end of the game. If the players can destroy the creep structures in time there will be a complete reset but the second time around they will only be given a 1 minute timer. The timer could continue decreasing, but it could also stay at 1 minute; both seem viable.
EDIT: Accidentally made this in General. Can a forum admin move it to the proper sub forum? Thanks