Seaside Hill (Sonic Generations)

Seaside Hill is one of the levels in the game Sonic Generations. It represents Sonic Heroes in the Dreamcast Era of the game. Enemies such as the Egg Pawn return. This stage has some references to other stages, like Hydrocity Zone, Jungle Joyride, Ocean Palace and Labyrinth Zone. It is exclusive to the PS3, Xbox 360 and PC versions. Modern Sonic speeds through this zone along looping alabaster highways and aquaplaning over the water as in Adabat, and may choose to either jump along the backs of giant turtles or drive a go-kart on a suspended road. Classic Sonic, meanwhile, takes to the submarine underground in temple sections reminiscent of Hydrocity Zone and Labyrinth Zone and has to run away from giant spiked rolling stones towards the end. As both Sonics can be underwater for good portions of the level, air bubbles are also back in this zone. This issue can be remedied for Classic Sonic if the player has the Aqua Shield equipped.

Act 1
The wheel chase from Ocean Palace returns in this level. There are also underwater portions making allusions to Hydrocity Zone and Labyrinth Zone. Surfing was also hinted at as a power-up for either Classic or Modern Sonic in this stage, but this feature is not present in the final released game.

Act 2
In 3D sections, running on water is a feature. The moving ruins from the original Seaside Hill return in this level, as well as the Egg Pawns, with some new enemies like Spinners. A quick step section similar to ones featured in Jungle Joyride and Planet Wisp makes an appearance as well. The karts from the original stage return, featuring modified controls. Modern Sonic is also able to ride on the back of a turtle.

Act 1

 * Rescue the Animals!: Save a set number of captured animals from Capsules and reach the goal in time.
 * Doppelganger Race!: Face of against Sonic's double and beat him in a race to the goal.
 * Espio: Way of the Ninja: Press Triangle/Y to have Espio attach a rope to the hooks and reach the goal in time.
 * High-Speed Hijinks: Enemies move and shoot at double speed. Try to get to the goal in time!
 * Underwater Challenge: Keep an watchful eye on the underwater terrain and get to the goal in time.

Act 2

 * Rouge: The Temptress: Press Triangle/Y to have Rouge take out enemies using her wiles and reach the goal in time.
 * Doppelganger Race!: Face of against Sonic's double and beat him in a race to the goal.
 * Trick Island: Use Rainbow Rings to pull off enough tricks and reach the goal in time.
 * Surf, Sea and Sand: Take on various course and find your way to the goal before time runs out.
 * Terror From the Deep: Skim the water's surface and try not to get chomped by a giant Chopper. Get to the goal in time!

Characters

 * Sonic the Hedgehog (Classic and Modern)
 * Espio the Chameleon (Rescued character, Mission for Act 1)
 * Rouge the Bat (Mission for Act 2)

Enemies

 * Egg Pawn
 * Spinner
 * Electro Spinner
 * Chopper

Trivia

 * Certain parts of Classic Sonic's level are much like sections of Hydrocity Zone and Labyrinth Zone. Perhaps this is Sega's way of providing more variety to the levels, as they most likely knew that certain levels would look too similar to each other. This also makes Seaside Hill the obligatory "Water Level" that appears in most Sonic games, though it's like Aquatic Ruin Zone in which more experienced players can get through the stage without touching barely any water at all.
 * Seaside Hill forbids you from taking unnecessary shortcuts. The water around the stage is marked off by buoys, and whilst Modern Sonic can run on water, if you venture outside of the safety area, you have approximately 2 seconds to make it back or a Chopper will emerge from the sea and eat you.
 * This is the first time you can go underwater in this stage. In Sonic Heroes and Sonic and Sega All-Stars Racing you would die upon going underwater.
 * Unlike in Sonic Heroes, Tails and Knuckles are not playable.
 * As a result, the kart controls are modified. Only Sonic rides the kart, and it is possible to boost while using it.
 * The kart segment is similar to Sonic and Sega All-Stars Racing, as Seaside Hill was redone into a race course for that game.
 * This stage can be debated as Ocean Palace as well as Seaside Hill, as it not only contains portions of the Ocean Palace level, but also shares its music in the Modern Act.
 * This level is placed in the Dreamcast era, despite not appearing on said console. This was done to make each era have an equal number of levels.
 * The Egg Pawn is the only returning enemy in this stage, since the Spinners and Choppers never appeared in this stage.
 * Strangely, Spinners replace the Egg Flappers as the flying enemy.
 * This is the only level in the Dreamcast era that doesn't take place in a city.

Videos
thumb|left|300px|Modern and Classic