We released a new mission today, Gallehault. Gallehault is massive and combines a wide variety of threats, from a wide variety of directions. In Gallehault you will face massive swarms, air assaults, cruisers, healers, face units rushing your colony and waves targeting other sites.
Gallehault starts you with two metal refineries and a fission reactor. But it's large map is going to make it difficult to defend all of them (I've never been able to defeat Gallehault with sacrificing at least two of them). It's fair to say that every mission so far has been training for this one.
Lots of paths means lots of ways that enemies can attack. Spoiler: on Thursday we are planning on releasing an update which shows the path for selected units which is helpful on maps like this (you can check out the details of that update here: https://forums.stardock.net/494618/page/1/#3747442).
Some paths are heavily used, some are rarely used, but they cannot be ignored and allow a enemy wave to sneak up on your colony.
Deciding what to defend, when and where to use your orbitals will be the key to success. Overspend on one area and it's almost certain death.
Though Gallehault has a lot of paths, it also features a number of choke points that are fun to build death traps in. Just remember that not all enemies will go through this choke point.
The swarms on Gallehault are larger than any mission so far. Fortunately the long ravines give you a lot of time to whittle them down, or to pick a point to make a stand against them.
I can't offer a single strategy to defeat Gallehault. Each way brings a new threat. Watch your minimap well, remember that you can mouse over the unit icon in the wave panel to see what direction future waves will come from. And when all else fails, Milton is a great last resort.