This mobile game named Planet Guardian is a very pleasant game which is available here absolutely for free. Planet Guardian has a vast list of categories, for example one-player and action and many more such as arcade, defense, space games as well. This is an HTML5 game and games like these has no problems running on mobile phones. The controlls are easy, just use your finger on mobile and mouse and keyboard on PC to navigate through the game. Have fun playing Planet Guardian online game for free on www.AiFreeGame.com.