Malden is the third mission of the Siege of Centauri campaign. It is the first mission to feature multiple entrances and a fission reactor that provides radioactives to power our orbital abilities.
So right from the start I have to consider where my enemies will be coming from, and how to defend two positions.
Mousing over the enemy icon in the wave panel shows me where that enemy will be coming from. In this case, this Reaper swarm is coming from the east. Good, that's nowhere near my Fission Reactor, so I can focus on defending my Colony without worrying about losing those sweet, sweet, radioactives.
I expect to kill a lot of enemies around my Colony, so I put a Scavenger Module there and a nearby Arc Projector. The Scavenger Module converts any enemy killed within its radius into metal that I can use to build more towers. I also put a Gun Turret along the path just to whittle enemies down a bit on their way to me. Gun Turrets are cheap, and I hate to waste good positions on them, but this remote part of the path seems perfect.
Since I only had enough metal for one real damage-dealing tower, I'm going to need some help when these Reapers get to my Colony, so I deploy Milton. He isn't permanent, but with his double chainguns and a backpack full of missiles, he deals lots of damage in a hurry (and makes my Scavenger Module very happy).
Meanwhile, the western path up by my Fission Reactor has its own problems. The metal from Milton's destruction comes in handy and I'm able to drop some towers that are better suited for dealing with the more hardy Destructors and Corrupted Healers. Two Plasma Cannons and a Corrosive Mortar help, but I also need to drop some reinforcements to keep them from wiping out the fairly fragile Fission Reactor.
The Fission Reactor does have some minor drone defenders of its own, but they won't survive long against a sustained assault from Destructors. I am able to defend the Reactor, so I will have more radioactives to play with for the rest of the mission.
Designer thought: I should really make it so that a Fission Reactor explodes when destroyed, damaging everything around it.
But metal spent defending the Reactor was not spent defending the Colony, and soon I have a rush of very fast Masochists trying to destroy it. A web of Arc Projectors eventually destroys them, but my Colony takes some damage in the process.
A larger wave of Reapers attacks my Colony from both sides. They seem to be ignoring my reactor for the time and focusing on my colony.
But the bonus radioactives allow me to deploy Milton again and fulfill one of the mission's secondary objectives of killing 100 enemies with Milton, which isn't too hard against the large swarm.
Which leaves one wave left. A Clutch of Eggs that has considerable defenses and decides to go toe to toe with Milton.
I drop another Plasma Cannon and Corrosive Mortar to help Milton out, the Clutch of Eggs is destroyed, and the Colony is saved.
How would you beat this mission?