Defend your fortress from the oncoming enemy waves. Place turrets in locations of your choice on your fortress, creating the best defense possible to withhold even the greatest of attacks.
Eliminate the invading force intent on taking Space Station Xorbe in Earth's orbit. If the station is captured then it'll become a staging ground for the invasion of Earth itself. You got a huge arsenal of weapons and defensive mechanisms to stop them.
The mafia war has begun. You have to protect your territory against the enemy gang that tries to take over. Bring your armed men to the roofs to shoot and destroy every outsider moving in on your turf.
Place towers on the way of minions of evil pirate who wants to destroy your cake factory. Add special ingredients to towers and make unique recipes that will help you eliminate your enemies.