Nigh Pilago had once been covered by a single vast ocean, but had been drained to the point where chains of small islands began to appear. The planet is especially important to the ARM, for its seas are a chief source of water, a necessity for ARM units. Additionally, the presence of a Galactic Gate leading to the Empyrrean System further reinforces its strategic importance.
This planet is pretty much Thalassean, except that you are playing as the CORE, plus you have access to Tier 2 ships and aircraft. There isn't much land to work with, plus there are very few Metal Deposits to go around, so you may need to construct some Metal Makers. Tidal Generators and Wind Generators will be especially useful, the latter because of the planet's high winds. Additionally, you may want to rely on aircraft more than ships for most of the missions on Nigh Pilago.