Kingdom Rush

Kingdom Rush is a tower defense game set in a medieval fantasy setting. Levels are composed of a number of pre-set roads that enemies march across, and the player must defeat them before they reach the end of the path and drain lives to cause a game over. To prevent enemies from reaching the end, the player must purchase defensive towers at set points around the road to attack any incoming monsters.

The player can choose between four types of towers to place: archers, mages, artillery, and barracks. Each tower type has its own distinct strengths, such as artillery being more effective against grouped monsters, archers better at targeting flying threats, and barracks training soldiers that attack in melee and slow down enemies. Slaying monsters gives the player gold, which they can use to buy more towers or upgrade existing ones. Each tower type can be improved three times before the player must choose between two final upgrades with their own distinct abilities. For example, the final upgrade for a mage tower could be either an "Arcane Wizard" that shoots magic beams and teleports monsters back down the road, or a "Sorcerer" that summons a defensive earth elemental and weakens enemy armor.

Kingdom Rush was developed over the span of six months by the Uruguay-based developer Ironhide Game Studio. The studio had been founded in 2010 by Álvaro Azofra, Pablo Realini and Gonzalo Sande, who conceived Kingdom Rush as their first major project after working on a number of minor Flash games. After seeing the success of tower defense games, the three decided to replicate the basic strategy of the genre, combining it with elements of other games they played in their youth. The medieval theme was inspired by references of knights and wizards throughout popular media, in addition to the team's experiences as Dungeons & Dragons players.

The programming was managed by Realini, and Sande's art design focused on creating a detailed, cartoony style. The team received no feedback during the development process and had run out of money and savings by release. The initial Flash version of the game received one of the most favorable ratings on Kongregate and was a financial success. The studio brokered a deal with their marketer and publisher Armor Games for ports to mobile devices.

According to the review aggregate website Metacritic, Kingdom Rush received "generally favorable reviews" for its iOS version.

Critics considered Kingdom Rush to be a standout tower defense game, with reviewers calling it memorable, and "an instant classic". IGN and Paste applauded the graphics, believing that they set a lighthearted mood that complimented the gameplay. Pocket Gamer wrote that the visuals and sound effects created a "sense of fun" that prevented gameplay from becoming tedious or repetitive. Eurogamer further appreciated the art, writing that it acted as a distinct element of the game that complemented its upgrade systems.

The success of Kingdom Rush prompted plans to help grow the games industry of Uruguay, which had a small number of developers and lacked a formal developer association at the time of release. Ironhide Game Studio later added in-app purchases to the game to help monetize the game's success. The team began development of a sequel called Kingdom Rush: Frontiers, which they decided to self-publish. Frontiers was planned to expand upon the narrative presented in the original game while presenting new upgrades for towers and skill trees for heroes.

The franchise was further supported when the developers released comic books that built upon the story. Kingdom Rush: Frontiers was first released on June 6, 2013, for iOS, receiving "generally favorable reviews" according to Metacritic.