Thanks for trying it. The controls are shown on the page. It's pretty easy once you know how to play.
Basic Controls:
Use left mouse button to drag a lasso around your ships then left click a planet to send them.
Right mouse drag to select multiple owned planets to start a rally then left click a planet to set the rally destination.
Middle mouse drags the map and wheel zooms in/out.
Basic Play:
Capture planets to produce more ships faster (Basic, Medium, Heavy, then Titans after owning a planet for 5 minutes).
Planets ramp up production to heavier ships over time.
Build up frontlines to send in big waves to take enemy planets.
Destroy all factions to win (Conquest) or Capture And Hold the target planet for 5 minutes or destroy all factions to win (Capture & Hold).
I hope that helps.