There are different enemy units in the game. Beginning with some small fighter jets and finishing with heavy cruisers. Each one has its own unique characteristics.
Light fighters: Very fast small space ships. One is not a big problem, but ten or twenty of them can cause lots of trouble to your base.
Assault ships: Dangerous combination of speed, fire power and persistence.
Cruisers: Heavy armored space fortress. Even a single ship can cause a lot of damage. Strong offensive weapon, and rapid firing pulse towers make them deadly opponents on a battlefield.
Spaceships looks good.
Thank you.
Do you plant to add more spaceships to the game?
Maybe in future updates. I've thought about game mode with some big ships, like bosses.
Very impressive. Going to track this game. Keep it up!