Aliens have OCs for defense.
The aliens need more structures to defend/atack key points across the map.
So, we have 4 branches.
Defend:
Spike Chamber: The current offense chamber. 10 resources. Shoots a spike for 15 damage, at about a rate of 1/second. This damage doubles if the chamber is near a hive. 1000 health.
Alien Specific defense:
Acid Mine: (not under this chamber branch at all, it's a fade attack). A fade attack, put in slot 3 (replacing metabolize). The fade shoots a mine, which will instantly plant itself when it lands. It has an arcing flight, like bilebomb. When stepped on, it will explode, doing 75 damage to all nearby marines, and 150 damage to all nearby structures. Uses 90% of the fade's energy. RoF: .1/second.
Spore Mine: Costs 10 resources. A gorge can purchase a spore mine. Inside this sporemine is an extremely powerful version of spores, doing a massive 6 times the damage/second (42 damage/second). This lasts for 7 seconds after explosion.
Offense:
Vibration Chamber: 75 resources. Takes 120 seconds of being used to build. 5000 health. Slightly smaller then a hive. This chamber senses all marines around it within a 750 unit radius. It will then send vibrations (like the onos stomp) in all directions around it, any time that a marine is sensed. These vibration can travel up to 1000 units, and travel at 500 units/second. They cannot go through walls, however can follow turns in hallways. Any marine that gets hit will take 250 damage. Marine structures, if in the path, will take a minor 50 damage. RoF: .25/second. These vibrations can be jumped over, much like stomp.
Infestation: 300 health. The gorge can build infestation. For every 1 resource spent, a small area is covered. This will stick marines to it for 4 seconds, and the marine will not be able to move/shoot. He will also take 10 damage/second. This can be destroyed with any weapon, but all non-explosives do 1/2 damage.
Upgrade:
Defense Chamber: 15 resources. Provides the Regeneration, Carapace and Redemption upgrades. Regeneration nerfed to only heal 2% health.level, but now 1% armor/level is healed, while health is being healed (and regen from health overflows). Redemption buffed to 50%/level/second. Carapace always adds an extra 1/3 of your armor/level. 1250 health. Also heals nearby aliens/alien structures at a rate of 25 health/second.
Sensory Chamber: 10 resources. Provides the Cloaking, SoF and Focus upgrades. Cloaking now makes you 90/95/100% invisible from level 1-3, along with the faster cloaking. Focus now adds a 25% boost/level to damage to all attacks, and no longer slows down RoF. 800 health. Any marine near a sensory chamber will appear on hive sight as a blue circle. Also, the sensory chamber will parasite marines that touch it. Extends the range of all nearby (500 units) chambers by 150 units (my favorite idea). This does not stack.
Movement Chamber: 15 resources. Provides the Celerity, Silence and Adrenaline upgrades. Celerity raised to 35 units/second/level. Adrenaline raises energy gain by 4%/second/level, instead of just 33% faster/level. 1100 health. Any alien within 450 units of a movement chamber will gain a 15% boost to speed, and a 10% adrenaline boost every 3 seconds. Both of these stack. They also can travel to a random hive that is not the closest hive by "+using" the chamber.
Advanced: These are chambers that will help your team immesely, more then any other chambers.
Resource Tower: 15 resources. 3500 health. Gives your team 1 resource every 4 seconds. .2 seconds/resource are taken away with each alien on the team (so in a 10 vs. 10, each RT makes resources 2 times as fast).
Hive: 50 resources. 12000 health. Allows a new upgrade chamber to be built. Also unlocks a new ability. Any alien within 600 units of it heals by 15% health, gets a 20% faster RoF on all attacks, and all attacks are 25% stronger.
Just my ideas...