This game was classified by the community with the following category scores - Violence=1/3, Sex=0/3, Mature Content=0/3. Orb Tower Defense is an elemental-based tower defense game featuring an online game mode with up to six players and three different singleplayer game modes. The towers and creeps can be one of the following elements: fire, water, plant, electric. Each element has strengths and weaknesses to each other. Every type of tower has a total of six possible upgrades.