Complex sentence: Atari originally wanted to release this game in 1983 but was delayed due to technical issues and difficulties so it was returned to the lab for further testing and research which was not fully and officially released until June 1984.
Split into simpler sentences: Atari originally wanted to release this game in 1983, but it was delayed due to technical issues and difficulties, so it was returned to the lab for further testing and research. It was not fully and officially released until June 1984.