Your objective in this tower defense game is to prevent enemies (which come in waves) from entering the base through the bottom entrance by setting up towers, traps, etc. You can play up to 30 waves in campaign mode or unlimited in survival. Set up your towers strategically, but if they don't get the job done, you can take control of them yourself without a limited range by selecting a tower and pressing "C" KEY. Use YOUR MOUSE to control the game. At the end of the game, you're judged with a score by how well you defended your base and you can submit it to a leaderboard. Good luck!
All the instructions you need are in the game, Have fun!