Editing Sonic the Hedgehog 4: Episode I (section)

===Leaks, delay and fan-reaction===
In February, a build of ''Episode I'' was submitted to Xbox Live Arcade's PartnerNET service, where developers were given access to upcoming downloadable titles for testing purposes. Soon after, screenshots, music and progressively more gameplay footage were leaked onto the internet. Eventually, a playthrough of the entire game was leaked and Sonic Retro, which had already banned leaked material when more than they approved of had been released, responded by banning ''Sonic 4'' discussion for several days. As well as this, PartnerNET shut down for a night. Other websites also made efforts to crack down on leaks, such as banning posting of leaked content. The build was controversial, due to it containing "floaty" physics speculated to be due to it using the ''[[Sonic Rush]]'' engine, poor animations and criticized the level design features such as gimmick-based acts that were disliked by most fans.

On 20 May 2010, Sega announced that due to fan input, the game would be delayed until later in 2010, in order to extend the development of the game. They stated in game magazines and online that this was specifically done to allow various fan requests (since the game was leaked) to be implemented, including more momentum-based level designs and improved physics closer to that of the [[Sega Mega Drive]] titles.

Releases for [[iOS]] devices were also announced, finally ending speculation of the fourth unknown platform, although it was leaked months before when images were found in the website's source code. It was also revealed that the iOS version would receive two extra levels, which turned out to be the Mine Cart and Pinball gimmicks stages in [[Lost Labyrinth Zone]] Act 2 and [[Casino Street Zone]] Act 2, which were heavily criticized in the leaked gameplay footage. Sega said this was done because the levels fit the mobile controls more. Fans speculated that the console versions would receive new, non-gimmick levels to replace them. Sega confirmed this with pictures several weeks before the final release. The new, console-specific levels were much closer in design to the other levels and featured new gimmicks which require platforming.