Piñata‘s is a collection of five Atari 2600 homebrew games on one cartridge including arcade, action, and adventure: Heartbreak, Ping, Joyride, Fix-It Felix Sr., and Flipside. All games were made by Cybearg the past half year. It should be 100% compatible with emulators and cartridges like the Harmony.

http://atariage.com/forums/topic/217123-pinata-2600/