bomblik has released GNU ROBBO which is a Homebrew Game for PSVita, GNU Robbo is a free open source reimplementation of game designed by Janusz Pelc and published by LK Avalon in 1989 for the Atari XL/XE computers. It was released in the United States as The Adventures of Robbo.

More info can be found here --> http://gekihen.customprotocol.com/en/project/GNU-Robbo