So I beat this surprisingly "interesting" mission at last. There are some tips regarding this mission in other threads, some repeated here. I noticed one quitting the game because of it, not too weird consider how confusing it is if you just take it at face value.

Here is my version for those interested:

Early phase
1. Don't build "diggers"!
2. Upgrade your laser lab(!). Yes, you have one. No, you cannot build one.
3. Build subterrain guns and laser turrets continously until you have relanded your frame and it looks safe. Subterran guns you spread out, laser turrets around the edges and typical entry points to your base. Put some extra generators too.
4. Move your one squad right outside the range of your opponents turrets, build officers (roughly twice as many officers) and technicians until you can morph a lot of scumers (my first squad had 14)
5. Keep (re)building defenses all the time until you have crippled your opponent, play at half speed if you can't keep lasers/chasers building constantly at normal speed.

Mid phase
1. Your first squad should take out energy and sub terrain guns, also move by the frame to force it to lift. Your opponent will reland his frame IF:
- a: you are not beneath it anymore
- b: The terrain in his landing zone is not damaged
2. Build a command center for a second squad, reinforcing the first is not trivial. Send it to take out newly built generators. Make sure the opponent frame always has some terrain damage where it wants to land. My second squad was much smaller.
3. If your base is still not safe, micro shields on/off, build extra generators/defense as needed. If things go well, your opponent is now lacking energy and tech to hurt you much anymore.

Last phase:
1. Build a third command center, make units until max and send this final squad into your opponents base.
2. I had to wait for the alpha-portal to travel all the way around to enter it
3. Make sure your opponent does not land his frame, keep your smallest squad on patrol through the landing zone, the rest you flatten buildings with.

Dude, thank you so much! I was nearly giving up because of this god forsaken mission!

Great to hear! Nothing like completing missions that seem impossible :)

Thanks for posting this. I was getting really frustrated with this mission. The mission is quite fun with your strategy.

Yes the mission is quite fun when you get going! Nice game, maybe I'll play through it again some day.

here is the Biodamage video guide: http://www.youtube.com/watch?v=jyHtbBiA2LE

Build max scumer(~20) in one squad, then,get ready the second Command Center for the next squad, With the first squad take out first the Subterra Chaser Guns, then the "Key" generators. Build the next squad of scamers ,take out the rest of the generators. Make sure you replenish your two squads with Officers and Technicians. Be patient, because it will take a while for the Alpha Portal to come around(normal difficulty)

how come the attacking things at the beginning are glowing red in this video? i see only damaged ground.

also, what is that first attack and how can i defend against it?

the game really sucks at introducing new units. no explanations whatsoever. learning by trial and error and relaunching every mission several times is not exactly fun.

The glowing red things are : Scummer - Middleweight underground unit with special terrain-boiling sys-
tem that disrupts the surface as the unit moves. Requires: Lvl 2 Laser Laboratory, Lvl 1 Subterra Laboratory,

to defend against them, you will need: Subterra Gun - Cost Damage Construction requirements 200 24/30 Lvl 1 Subterra Laboratory Fires torpedoes capable of hitting underground targets to defend against them.(manual helps,some....)

Yap, this game is all about learning by trial and error and/or many hours of frastration......are you up to it?

here is another guide: https://www.youtube.com/watch?v=6i6D7pU7eJg