Ratchet & Clank: NEXUS was planned to be released in 2006 for PlayStation 2 but was cancelled. It was developed to a concept stage by Insomniac Games and it continued the Up Your Arsenal storyline. After the game was canceled, it was replaced by Ratchet: Deadlocked with many of the ideas reworked into the Deadlocked storyline.
Message from Insomniac Games
"Following Up Your Arsenal, we entertained the idea of putting our heroes on a singular planet. The design revolved around a global conflict between two alien races and we thought it could be interesting if Ratchet and Clank had differing ideas about the war. Eventually the project changed direction to become Ratchet: Deadlocked, although the idea of one planet stayed with us and reemerged in All 4 One."
- Ratchet & Clank - 10 years of concept art on the Insomniac Games website.