|This location exists primarily or exclusively within the Sonic Boom continuity.|
Information in this article may not be canonical to the storyline of the games or any other Sonic continuity.
Sonic Boom: Fire & Ice
Seaside Island is the second level in Sonic Boom: Fire & Ice. It is a tropical island with jungles, beaches and ruins, and the home island of Team Sonic. Due to Dr. Eggman, the island's environment was messed up by the by-products from the doctor's mining operations on Ragna Rock. This pollution was brought to an end by Team Sonic.
Seaside Island is a tropical paradise with palm trees, sandy beaches, lush jungles, grassy hills, round-leaved bushes, and clean pools of water. Alongside the nature are also boat docks, surfboards, tikkis, outdoor furniture, and the huts and earth house residences of Team Sonic.
The first two adventure levels are set on the coast. Here, palm trees, round-leaved plants, flowers and spiky coral adorn the sandy stone paths. Also, surfboards and wooden bridges/roads occasionally appear on the paths, and some palm tree trunks form roads. In the background are also the island's tropical bays, with sanddunes, cliffs and palm trees on the beaches and small islands in the sea.
The last two adventure levels are set in the dimly lit jungle on the beach. The paths lead through the ancient ruins of a forgotten civilization, much of which are covered in overgrowth and deadly flowers. Giant winding trees with moss on them, jungle flora and ancient structures cover much of the background, except for a number of openings that show the island's coast just beyond the jungle.
While mining on Ragna Rock, Eggman would pipe the messy by-products from his operation off to Seaside Island. This lead to the creation of fissures emitting Fire and Ice energies, which would mess up the island's environment.
When Sonic, Tails and Amy came to Seaside Island to seal the fissures that had erupted near the Village, they found Sticks fraternising with D-Fekt, whom the badger found overly loveable. As the trio tried in vain to convince Sticks that D-Fekt was dangerous, a sudden fissure eruption distracted the group, allowing D-Fekt to escape.
Believing D-Fekt had a connection to the fissures, and, by extend, the recent strange weather patterns, Team Sonic followed the robot across, and eventually off Seaside island. Along the way, the team found Knuckles and got him to come along with them after a brief misunderstanding.
Like in other areas, the adventure levels in Seaside Island are divided into two parts (the foreground and background) that run parallel to each other, which can be traveled between with the Bounce Pad. Other than the Bounce Pads, standard gimmicks here include Boost Pads, Enerbeam Swings, platforms that move when stepped on (if they are not already moving), Rails, and disappearing platforms. There are also constantly-moving block platforms and cannons for firing the playable character, the latter of which can be fired with . Most noticeable though, are the blocks of ice/water that can be turned solid or intangible by touching them while using Fire/Ice Mode.
Hazardous obstacles in the adventure levels include stationary rollers with spikes, moving and non-moving spiked blocks (some of which form traps), and spiked surfaces. Touching such obstacles will damage the player and return the characters to an earlier position. The adventure levels also have collectibles scattered about which unlock extra content if collected, breakable obstacles that give extra Rings, and Challenge Room entrances.
Like other levels in the game, Seaside Island's adventure levels have several character-specific gimmicks for the playable characters. These include Air Vents, laser blocks and Laser Reflects for Tails, pillars for Amy, Burrow spots for Knuckles, and Boomerang Switches for Sticks. In addition, Seaside Island features three bonus levels, each with different gameplay mechanics
Sand Drift is Seaside Island's first adventure level, which takes place on the coast. It becomes available after unlocking Seaside Island. Clearing it unlocks Sticks.
At the beginning, follow the paths that appear in the right direction until the characters get sent into the background. From there, keep going right again to reenter the foreground, and continue going right from there. By following the path along the bottom of the level, the player will come to a fork intersection with an ice block on the left and a water block on the right. Going left here takes the player for a loop past Overgrowth, while going right here and following the bottom route at the start will take the player to the fissure.
|Reach goal in 02:50 min||Ragnium|
Sunken Caverns is a bonus level where the player must navigate an undersea section with mines and breakable obstacles in the Sea Fox and find the lone Trading Card within the level in time. It becomes available after clearing Sand Drift.
|Find the Trading Card in 00:40 min||Ragnium|
Brambling Beach is Seaside Island's second adventure level, which takes place on the coast. It becomes available after clearing Sand Drift.
At the start, begin by going right on the path. Along the way, after the second Boomerang Switch, the player will enter a large room with a road on top that leads to a loop past the Boom Temple. If the player keeps going right in this room instead, they will come to the first cannon that will shoot them up to a split in the path. Go right from there to get to the second cannon which leads to another split path. Going left here takes the player around for a loop while the right path will lead to the fissure.
|Reach goal in 02:30 min||Ragnium|
Iceberg! is a bonus level where the player must clear an iceberg passage filled with destructible ice bergs, indestructible mines and whirlpools in the Hovercraft and collect the Trading Card at the end in time. It becomes available after clearing Brambling Beach.
|Reach goal in 00:50 min||Ragnium|
Tangled Tropics is Seaside Island's third adventure level, which takes place in the jungle. It becomes available after clearing Brambling Beach. Clearing it unlocks Knuckles.
At the start, follow the rightward paths until the characters get sent into the background. From there, keep going right again to reenter the foreground. Keep going right again to reach a platform that moves across a spike pit and scale a series of disappearing platforms. On top of these platforms, go left to find a loop past Jungle Glade or go right and follow the rightward paths to enter the background where the fissure is.
|Reach goal in 02:10 min||Ragnium|
Fiery Duct is a bonus level where the player must race to the end of an obstacle course while dealing with fire and ice elements. It becomes available after clearing Tangled Tropics.
|Reach goal in 01:35 min||Ragnium|
|Reach goal with 200 Rings||Ragnium|
Dusty Trail is the Bot Racing minigame of Seaside Island where Sonic or a Bot Racer competes in a circuit race against Giant Robot on Thunder Island. It becomes available after clearing Tangled Tropics. To clear it, the player must complete three laps before Giant Robot.
|Win race in 02:20 min||Ragnium|
|Win race with 200 Rings||Ragnium|
Lost Pyramid is Seaside Island's fourth adventure level, which takes place in the jungle. It becomes available after clearing Dusty Trail.
At the start, proceed down the rightward paths (through the Burrow sections). After the second Checkpoint, the player will enter a large room with Tangled Mount in the upper left corner. From here, proceed down the rightward paths again. Just before the third Checkpoint, the path splits in two. Taking the upward route leads through a loop, while the right route leads to a Burrow section. After this section, take the left path to get sent into the background and reach the fissure.
|Reach goal in 02:30 min||Ragnium|
Sonic's Shack is Sonic's residence. Here, the player can listen to the game's soundtracks, replay story cinematics, or unlock concept artwork from the Sonic Boom television series with Ragnium. It becomes available after clearing Sand Drift.
Tails' Workshop is where Tails tinkers with his inventions (although the building itself looks like Tails' House). Here, the player can assemble Trading Cards with the pieces found in the levels to unlock new Rival Race tracks on Thunder Island. It becomes available after clearing Sand Drift.
Amy's House is Amy's residence. Here, the player can select a new skin for Amy's Hammer in gameplay depending on the amount of Hammer Parts they have collected. It becomes available after clearing Tangled Tropics.
- This level is a remake of Seaside Coast from Sonic Boom: Shattered Crystal. It includes the same residences for Team Sonic as in Seaside Coast, and the paths between the access points for the residences and/or the levels are virtually identical to their predecessors. Additionally, several access points can be found in the same places as those in Seaside Coast.