Game bug:
Game forgets latest research and weapon purchases/upgrades.
If you refresh the game/browser your research and upgrades come back.
Other than this I think this game is great.
Game breaks when you have too many people. The people get stuck and will not move for long periods of time.
Also, the sometimes refuse to move resources unless there is a direct line of sight between depots.
While I like many things about this game I have found it impossible to win. There seem to be many other people who are also frustrated by this, please fix this game so it is actually winnable.
What do the hearts do?
I think that you should increase the amount of money that you start with as you go up in levels or provide one or two free towers per level.
The end levels are too hard.
Additionally, what is the point of getting all the upgrades if the other racers are still have higher speed and acceleration?