Shoot all your opponents. In some levels, you are part of the blue team and you fight your enemies in a team effort. Make sure you do not kill your team members. And grab the bonuses before your opponents do. Create your profile before you start. This way, you can play the game just the way you like it best.
Use WASD or the arrow keys to move and Space to jump. Use your mouse to aim and shoot and the number keys or Q and E to change weapons. Press Tab to see your scores.