Contra: Evolution (known in China as Hún Dòu Luó: Jìnhuà Gémìng, or "Contra: Evolutionary Revolution") is a 2.5D sci-fi side-scrolling run-'n'-gun game released by Konami for arcades in Asia on 2011. It later received a mobile port worldwide for iOS devices on May 31, 2013, followed by Android devices on August 21, 2013.
A high-definition adaptation of the NES version of the 1987 arcade game Contra, Contra: Evolution includes four playable characters to choose from and a weapon loadout system (where players can switch between weapon power-ups collected at any time).
The game was initially released in the US app store in May of 2013, but was there less than 24 hours. This was because the version released was optimized for Chinese audiences, and it was pulled to make way for a western-specific version.