The large majority of fictional series develop in at least some minor manner within the course of their run. Characters are introduced, designs and concepts are altered, new pivotal plotlines are made forming a continuity. At times however the series is intended to be released in a particular order it is produced, with the final release order clashing with those plans, leading certain installments to come out in the wrong order, continuity is screwed up, changes in cast and scenario come and go and strange undeveloped elements seen in earlier installments
This can also occur due to communication difficulties with the creators. When a project is handed to numerous groups of staff, particular members
may be late or earlier on the ball for new changes or alterations made to the story, leaving rather different results from different teams.
- The pilot episode of The Simpsons "Some Enchanted Evening" was the final episode to be aired in the first season. This can be somewhat jarring due to the cruder animation and voice work compared to later produced episodes aired beforehand (part of the reason Groening was reluctant to air it beforehand).
- Also the third season episode "When Flanders Failed" was intended to be for the second season. Die hard fans may be able to notice the subtle differences in animation quality as well as the credits sequence.
- Similarly, the pilot episode for Sonic Satam "Heads Or Tails" was aired after the rest of the first season, particularly jarring due to using many undeveloped designs for characters and scenery (particularly Rotor and Sally) and story points that were altered later on (eg. Sonic's dog Muttski, who is not refered to in any later episodes).
- In a flip flop of this, the TaleSpin pilot "Plunder And Lightning'' was aired first as intended, but actually produced midway through the series. This results in several backstory plot points that are never refered to again in "later" episodes (eg. Kit's background with the air pirates).
- Both Sonic the Hedgehog 2 and Sonic CD began development around the same time. While CD was released last, it is much more akin to the first game, with similar graphics and physics. Perhaps most interestingly is Tails' absense outside a hidden easter egg image with the message "See You Next Game". Whether this was intended to be a promotional image for the earlier released Sonic 2 is unknown.
- Crash Purple/Fusion and Spyro Orange/Fusion uses characters from the then-in production Crash Twinsanity and A Hero's Tail. This causes oddities given how some were only given a proper introduction in the later titles (as well as the Fusion games completely improvising their personalities and roles).