Sonic the Hedgehog 4: Episode 1 (WiiWare JP prototype) is an early version of Sonic the Hedgehog 4: Episode 1 which was released on the Japanese version of the WiiWare service, accidentally on the release date. It contains many differences from the final game and includes different level designs and music changes. It shares a strong resemblence to the PartnerNet build, which in turn, also resembles the iOS version, although it is a much later build. It was built on February 9th, 2010.
* No way to progress to the next act without using the Level Select screen.
* Level select screen uses pictures of levels instead of a landscape.
* Levels use the loading screen briefly, instead of animating the title card screen.
* Several other graphical effects are missing. Sonic's "wheel-of-feet" animation only appears when Sonic is at top speed, and Sonic lacks his glossier shading from the final build. No motion blur effects are present in this build.
* The cutscene that transitions Mad Gear Zone to E.G.G. Station Zone is absent.
* There are some level layout differences.
* Casino Street 2 has a completely different song. It also lacks a speed shoes remix.
* Since there was no World Map mode at the time, the level select used the menu music.
* There was no transition between Mad Gear and E.G.G. Station, so this song is absent
* Super Sonic uses the invincible BGM as he hadn't had his own theme yet.
* Lost Labyrinth Act 2 lacks a speed shoes remix as there are no speed shoes in the level.
* Unlike the PartnerNet build, this version has the drowning music.
* There is no sound effect played when locking onto a homing attack target.
Splash Hill Zone
* The sunflowers in the background aren't fully animated; they are usually standing still. They also spin differently compared to the final build.
Casino Street Zone
* Act 2 contained the 100,000 Point Challenge, a short score attack level in a pinball-style area. Removed in the console version.
* Act 2 had a different music track which was appropriate for the score attack level. Replaced in the console version.
Lost Labyrinth Zone
* Act 2 contained the controversial Mine Cart level where Sonic remained in the cart throughout the level, which controlled poorly. It is controlled using the Wiimote's tilt function. The Mine Cart section is reduced greatly and plays automatically in the console version.
* The moving wall in Act 3 was much faster and harder to complete the area compared to the final version.
Mad Gear Zone
* The sirens in Act 3 do not play at all.
* Unlike the final build, the Special Stage is played by tilting the Wiimote.
Pretty sure the folks here wouldn't particularly condone pirating the game, so no direct links, but I will direct you to the thread this info comes from.
Haven't messed with it myself yet, but sure is interestng. Wonder what the differences between this and the PartnerNet leak have.