Outback Joey is listed as a Prototype in the online rarity/lookup guide, however it seems that it did receive a limited commercial release and therefore should be in the U.S. Game Releases section.
http://segaretro.org/Heartbeat_Personal_Trainer
http://www.helium.com/items/1820088-...-genesis-games

Blockbuster World Video Game Championships II was not commercially released and would be better described as a Prototype/One-of-a-Kind.
http://segaretro.org/Blockbuster_Wor...hampionship_II
http://www.gamesniped.com/2007/11/08...e-video-games/