You must defend city hall! Upgrade your buildings and objects to help do this, and don't run out of power! Click on a building/object to upgrade it. You cannot build new buildings.
If you upgrade a building or object all the way it gets a special power! Over time, tougher enemies start showing up. Oh and on a technical note, DO NOT play this on a windows 8 computer. I use a windows 8 computer at home and had to use other computers to develop this game in order to avoid lag; this was delayed by several weeks(perhaps even a month or 2 or even 3) because of this! I have decided to put this in "open test" since I cannot seem to run the game due to lag. Please report any bugs/lag in the comments. This game requires that fastest of computers, it tends to lag on some PCs.