Tidal Tempest is the third Round of Sonic the Hedgehog CD. Like with every other Round in the game, Tidal Tempest consists of two standard Zones that span all time zones, followed by a shorter third Zone set in the future which contains the boss. Geographically, Tidal Tempest is located on the Little Planet.
This stage takes place in flooded underwater ruins and thus resembles Labyrinth Zone to a great extent, featuring heavy use of typical underwater and winding, narrow passageways. At the start of the Round in the Present, the player can see a harsh, volatile landscape in the background, featuring rocky structures and volcanoes that periodically erupt every few seconds, lighting up the dark sky. By taking a few steps to the right, the player will plunge into the submerged underwater ruins. Stone pillars and plant life populate the ruins, and water pipes can be seen in the walls.
Each time zone has its own square block shape, and several blocks are grouped together in many clusters to form varying shapes or larger blocks that move in different patterns, though some can also crush Sonic. Buttons are placed in a variety of places and have many functions, such as opening up walls to reveal hidden rooms and passages, opening horizontal and vertical doors that close up behind the player once passed through, and small propellers found underwater that will stir up invisible forces that carry Sonic around the water. The player usually has little control while this is happening, but they can still influence Sonic's direction by holding or . Large pipes will carry the player from one point to another much like the water currents.
As well as its own gimmicks, this Round also features gimmicks normally seen in Labyrinth Zone, such as chained spiked balls as well as fast-flowing water currents that will carry Sonic through submerged corridors filled with spiked balls, complete with poles to grab on to so the player can align Sonic. Stone faces much like the Fire-Breathing Statues adorn some of the walls in the Round, except these faces spew out constant streams of water blasts that will push Sonic away in their direction along the ground. A good number of these gimmicks are non-functional in the Past. As with all water levels, keeping air supply filled using air bubbles is of the utmost importance when exploring underwater.
|A wondrous underwater ambience. If you advance without catching your breath from bubbles, you’ll be gasping. Go and watch out for the flow of unseen water currents.
— Sonic the Hedgehog CD JP manual (translation by Vertekins)
|As you dive into this underwater adventure, remember that you'll need air once in a while. If you go too long without it, a countdown appears. When the countdown reaches zero, you lose a Life.
Take a deep breath from air bubbles that drift up from certain blocks. Switches activate propellers, and the current will send you spinning. Grab onto the nearest pole to save yourself from steel spikes!
— Sonic the Hedgehog CD US manual
Differences between Time Zones
|The Present hasn't been touched upon so much by Dr. Eggman. Large pipes transfer water from different areas of this round, and secrets lie within the walls.
|Primitive caves and early plant life litter around, and fish are plentiful in the clean water. The water seems to be filled with seascum, giving it a darkened tint. Unique to this time zone are L-shaped platforms that turn when stood on. Keep an eye out for that robot transporter too, or...
|...Eggman will succeed in conquering these ruins. Everything has been completely trashed, including the water. Rusty ledges, broken pipes, dead plants — this place hasn't been taken care of for a long time!
|If you happen to stop such a devastating event from happening, you'll get this instead. This world is much different, like a giant aquarium, with plants in glass cases. The water level is at its highest in both Futures.
Certain versions of Sonic the Hedgehog CD have flaws rendering the water in Tidal Tempest. The Windows 95 version of the game relied on the use of palettes in 256-color mode in order to display underwater palettes, which were not carried over to the Sonic Gems Collection port due to most modern GPUs not properly supporting it. This leads to the water being rendered clear across all time zones.
The iOS and Android versions of the 2011 re-release also have issues rendering the water colour on certain mobile devices, causing the water to appear miscoloured. This does not apply to the Xbox 360, PlayStation 3 and Steam versions of the game.