In case you get confused, here are the controls and rules:
Arrow Keys - Move
Space - Select
R - Restart Level
Esc - Back
The goal is to march to every green government building on each level, and occupy them all. This means you need to add workers to your march by interacting with each factory (just step towards the factory when next to it). But when you have more than one worker marching, you can no longer turn around, so you have to find a route that allows you to reach every factory and government building without backtracking.
Police: A line of police can be pushed, if your line of workers is at least as long as the line of police. Or when possible, find another angle that allows you to push just one at a time.
Soldiers: Soldiers can be converted into workers. If each soldier in a group is adjacent (horizontal or vertical) to a worker, interact with any of the soldiers to convert the whole group. You can't convert part of a group.
Cell Tower: Occupy a Cell Tower to briefly take control of all the enemy units (police, soldiers) and take a single step with each of them. This is crucial for beating some puzzles!
You have a limited number of steps per level. If you beat the level within that limit, you'll get 3, 2, or 1 stars based on how efficient you were. You can lose a level if you take too many steps, or if you use up all your workers without occupying every government building.