I don't, as it fits into the story.
Actually, I would think it as a spin off if it had a different approach in the gameplay or the general structure of the game. Deadlocked, All 4 one and FFA can be considered spin off games of the main series and Secret Agent Clank from the non-canon. This game also is a reimagining that can be considered as an alternate, so not an actual spin off but something like a reboot.
Deadlocked? It's different from the other PS2 R&C games in both game-play and atmosphere, so I think it would count as a spinoff. Plus, it's one of the two games without both Racthet's and Clank's names in the title.
Honestly, I only consider SM and SAC spin-offs, as every other game is technically a part of the main series.
For me it would just be SAC, but even that one is debatable. Since it's canon as a TV show wihin the games I guess.
While it was definitely a change in overall style for the series at the time, I wouldn't call it a spin-off since the story followed Up Your Arsenal.
The new game for me is like an alternate universe not a spin-off game. It exists alongside the original series but both are removed from each other as far as what actually happens in their stories.
I mainly consider SM and SAC the only games that don't really fit the cannon of the series; there is just something off in their consistency to the whole lore of Ratchet and Clank that bothers me. These ones were developed by High Impact Games and I feel it shows… SM feels like a RaC game but Ratchet's personality sorta has a regression and he's back to being unpleasant like he was in the first game (although not as bad); it feels like most of his development as a friend to Clank was thrown out (at least that's what it feels like to me).
Now SAC I have to personally attribute my own fan theory to in order for me to accept it as any amount of cannon; where in, all of the game was a dream Clank had while being held captive in the mnemonic station at the Great Clock. In UYA Clank explicitly tells Nefarious that Secret Agent Clank is a TV show and is not real at all. Sure there are ways one might think of to say Clank became a Bond agent after the game but it really doesn't sit well with me. For me, thinking this game is all in Clanks head just makes everything work. For instance the series as a whole is self-referential a lot of the time and they rarely talk about the events of both these games (SM and SAC) later down the line (although that might be due to favoritism on the developer's part), any reference to Clank as a secret agent I think of his TV/ movie star role. Also, the nature of the mnemonic station is to access memories, so maybe while Clank was asleep for a year he was thinking back to his time playing the role of Secret Agent Clank but since he was dreaming it only borrowed from his memories. The series is also fairly chronological, unless stated otherwise for a game, and Secret Agent Clank originally released in 2008 the same year as Quest for Booty. So I feel it chronologically works with the setup of Clank captured and Ratchet looking for him. But that's just my two-bit theory…
TL;DR - RaC 2016 is not a spin-off; SM and SAC are, for me, spin-off games.
Has Insomniac ever officially stated if a game in the series was not cannon or a spin-off? I personally can't think of them saying if a game was called a spin-off or not, they kinda just expect people to figure it out themselves for the most part… or forget about certain games…
They did once state on IG Forums that they never wrote the stories for the PS3 games with SM and SAC in mind (thus they never get refrenced in any of them, unless you count the Prison Ratchet/Zoni skins thing)… They didn't directly say that these games are 'not canon', but well… They are not 
They did once state on IG Forums that they never wrote the stories for the PS3 games with SM and SAC in mind (thus they never get refrenced in any of them, unless you count the Prison Ratchet/Zoni skins thing)… They didn't directly say that these games are 'not canon', but well… They are not
They are not canon by IG but it's not like Insomniac is oversees them as the prison skin code exists. Either way they don't interfere anyway in the main plot in any way that creates a paradox, but just in case there is one IG wins.
They are not canon by IG but it's not like Insomniac is oversees them as the prison skin code exists. Either way they don't interfere anyway in the main plot in any way that creates a paradox, but just in case there is one IG wins.
Well, unless we know SAC is a dream/the series' episode, it does interfere with the main series pretty much…
They are not canon by IG but it's not like Insomniac is oversees them as the prison skin code exists. Either way they don't interfere anyway in the main plot in any way that creates a paradox, but just in case there is one IG wins.Well, unless we know SAC is a dream/the series' episode, it does interfere with the main series pretty much…
Well, in that case IG pretty much comes first.
Edit: Something just completely random. I was looking at high impact games, if they were doing anything new and I was looking at their game list (http://www.highimpactgames.com/games.htm). If you scroll at the bottom of the page there is Size Matters, their first game, and it seems that IG actually supported them in order to create this game. While they might not care about their plot they still these games on their mind.
I've always considered the original Ratchet and Clank games on the PS2 as a quadrilogy rather than a trilogy.
