Currently the most anticipated and talked about free online flash game is without question Gemcraft Chapter Zero: Gem of Eternity. Over the last few years, tower defense games have become immensely popular and the end of the craze is not in sight. Let’s have a look at the origin of these games and find out which games contributed to its success.

For those not familiar, tower defense or simply TD is a subgenre of real-time strategy computer games like Starcraft. The aim of the player is to try to stop enemies from crossing the map by building towers which shoot or affect them as they pass. Enemies and towers usually have varied abilities and costs and these get better and higher as the game advances. When an enemy is defeated the player earns money or points, which are used to buy or upgrade towers. The choice and positioning of the towers is the essential strategy of the game. The enemies usually run through a maze, which allows the player to strategically place towers, but there are also versions of the game in which the user must create the maze out of their own towers, such as Desktop Tower Defense. Some versions are a hybrid of these two types, with preset paths that can be modified to some extent by tower placement.

Tower defense finds its roots in the strategy classic Rampart, an arcade game from 1990. The game involved defending a castle by placing cannons and making repairs between several rounds of attacks. Its success resulted in the game being ported to a number of platforms including Super NES, Game Boy, Playstation 2, Xbox, Gamecube and most recently to the Playstation Network to offer multiplayer action. By the new millennium, tower defense games began to appear in user-created maps for Starcraft, Age of Empires II, and Warcraft III. Using defensive buildings or units as towers, these custom maps filled the online lobbies.

Eventually, independent game developers began using Adobe Flash to make stand-alone tower defense browser games, which led to the influential release of Desktop Tower Defense in March 2007. Hundreds of themes and gameplay variations have been tried out over the last few years including space and medieval settings. Child friendly versions appeared where players popped balloons or protected a picnic from ants. Protector was released late 2007 and was immediately ranked among the best, offering classes and specialization upgrades. More recently it was Gemcraft Chapter One: The Forgotten that took the crown by offering a new twist to the gameplay, the ability to combine towers.

The future looks bright for this genre and upcoming titles such as Gemcraft Chapter Zero: Gem of Eternity, Bloons Tower Defense 4 and Pirate Defense will surely set the bar even higher.