Splash Hill Zone is the first level in Sonic the Hedgehog 4. Released gameplay clips show a level very similar to Green Hill Zone and Emerald Hill Zone, and contains many of the same concepts, such as spinning sunflowers, Motobug badniks and oddly shaped palm trees. The level was featured in the official trailer on Sega's website and was the only playable level in the E3 2010 demo.
The Sonic 4 level select screen (along with the name of Act 3) seems to indicate that, at least in Splash Hill, the different Acts are set at different times of the day; a similar system to Knuckles' Chaotix. It was later shown that Act 3 and the Boss Act would take place at sunset.
||A beautiful coastal area filled with rolling hills and an everlasting feeling of summer, Splash Hill Zone is the embodiment of an adventurous paradise. As Sonic races through the smooth slopes and crisp rivers, he will also witness a spectacular sunset view from the top of the hills.
— Description on the Sonic 4 site
- Act 1 - The Adventure Begins
- Act 2 - High Speed Athletics
- Act 3 - Sunset Dash
- Boss - Showdown with Dr. Eggman
- Buzzer - Wasp enemy, flies and fires a missile at you then keeps flying.
- Bubbles - A blue, spike-welding bubble.
- Newtron - Disappearing lizard bot.
- Moto Bug - Insect bot that rides around.
- Chopper - A piranha bot that jumps from under bridges.
Splash Hill's "sunset" level select image can be seen at the top left in this development image