This is quite a hard map with some of the enemy units spawning after they die. The city on the northern side of the river will be attacked from different places. The enemy will try hard to take the town. You don't lose if it does, but it will give the enemy more reinforcements, making it only harder. The city is divided in specific area's. Some can be lost, but others will oppose you with more enemies when lost. Lay mines in such a manner that you can block the most important passages into the city.

Just like you, the enemy has a rail gun, which can be devastating on your units. Try to take it out as quickly as possible. You have four Goliaths that can be useful for this task, but you might need a perfect timing between the enemy attacks. Your other artillery is in range of enemy artillery so you best move it to the island in the middle.

Your first important task is to get four ambulances to a hospital on the other side. This won't be easy, because enemy squads have also landed on the south side of the river trying to prevent this. You have a sniper there; best to move him across the southern bridge to the island if you want him to survive. Get some squads and some armor over there as well to be prepared for the coming enemy squads. Once the attacks in the south are dealt with, you can safely pass the ambulances.

After a certain period, reinforcements will come to help you. Get the officer to the castle first and next to the city in the north. Once he arrives in the city, all enemy attacks will stop. You will then need to fulfill a few more missions to end the game.