What are some alternatives?
When comparing Fieldrunners and Robo Defense, you can also consider the following products
Bloons TD - It's time, once again to achieve total Bloon popping satisfaction, this time in the form of...
Kingdom Rush - Epic game of tower defense available across multiple platforms.
Bejeweled Blitz - Our games are sprinkled with a whirlwind of smile-inducing awesomeness and polished to a shiny sheen that keeps the world coming back again and again.
Towers of Oz - Towers of Oz for iPad, iPhone, Android, Mac & PC! Battle wooden soldiers, saber-toothed tigers and giant frogs in tactical battles as you defend the Land of Oz from the Dwarf King!!
Clash of Clans - Clash of Clans is a mobile strategy game set in a comically cartoon world of medieval siege warfare.
TowerMadness - Tower Madness is an epic 3D tower defense game for iOS.