Shield World (level)/Walkthrough

Quickly set up your base, get your Tech Level to at least 3 and start building Scorpion Tanks. Activate their Canister Shell Ability. This level also has several aerial Flood units, so it doesn't hurt to back the Scorpions up with several Wolverines (who annihilate anything aerial).

Clean the area for Alpha team first, which can be done with a fair amount of Scorpions. A Pylon will soon show up next to your base - have a Gremlin stand next to it to increase the time on your timer with a few minutes. You must do this at least once or you'll find yourself having very little time to complete this mission.

There is another Pylon just north (right) from Alpha Team's position, another Pylon can be found between approximately your base and Charlie's location, and the last is roughly between Bravo and Charlie.

Helping Bravo Team is more difficult, and will require a larger squad of Scorpions and support from Wolverines. When you finally reach Bravo Team, don't miss the 10th Black Box right at their pinned down location. If you want to collect the Skull in this level, use a Hornet to locate it (after killing 350 Swarms) northeast from your base. There will be several Flood Eggs there.

When you get to Charlie, manual assistance is mandatory due to the transporter being canceled because of the dangerous circumstances. Have a few Scorpions guide the whole Charlie Team back to the base and make sure you have several Scorpions back at the base as well, which will soon be attacked.

When all teams are evacuated, you have succeeded.