Barrier Eggman consists in a small room behind an impenetrable force field-like barrier. Within the room is a moving laser in the ceiling that is can be operated using a control panel just on the other side of the barrier. The Sonic the Hedgehog 2 version of this boss also has floating platforms with spikes below them.
Features and abilities
Barrier Eggman's moving laser cannon in the ceiling can be easily controlled with the control panel the room has. This can shoot powerful lasers that are deadly to its victims, although it requires a long time to charge.
A small hatch on the ceiling opens and small spinning platforms with spikes below them will arrive to float around the trapped room. A moving laser cannon will also appear on the ceiling of the cabin room, which eventually stops to load its laser attack. It will then shoot the laser to the floor before starting to move in the player's direction. After five seconds, it will stop shooting, turn itself off, and repeat its pattern over again.
The only way to get out of this trapped room is to destroy the laser cannon. This is possible when it stops and starts loading the laser cannon to its full power. The player must use the spinning platforms to reach the cannon, but they need to be careful not to touch the spiky undersides of the platforms, which can hurt the playable character. They also must make sure to not get hit by the laser blast that the cannon will shoot after charging enough.
By hitting the cannon eight times, it will be destroyed, which ends the battle. Unlike in other Zones, neither a Goal Plate or a Capsule appear to see the results, as Robotnik instead seen escaping to his space shuttle to travel to the Death Egg. After the player is freed from the trap room, Sonic arrives too late to the launch pad to stop the doctor, who has launched his space shuttle and takes off. After this, Tails arrives with the Tornado, now with a rocket add-on set below the biplane. After the sky chase, Sonic grabs hold of the ship and keeps hanging on until the space shuttle docks into the space station.
In this version, there are no spiked platforms (meaning that the player cannot attack the laser cannon directly); instead, the room becomes smaller every time that the laser is fired. To survive this fight, the player only needs to avoid the laser fire a certain number of times. Although they must survive the laser to win the fight, it is possible to hit the laser cannon's eye using Tails' tails while flying, but doing this will not affect the fight.
Eventually, so much of the room is damaged that the barrier falls on its own. Robotnik panics, and escapes to the outside of the air fortress. After that, the player will follow Robotnik to the outside and must to pass through the last platforming section of the Zone, where a long platform will raise up which the player must stay clear of until the end of the route, or they will eventually be crushed between the long platform and the ceiling. After this, the player will be able to ride up on the long platform for a moment, when the Zone's boss (the Hang Mobile) arrives.
In other media
Sonic the Comic
In Sonic the Comic, Barrier Eggman appears as one of the many features of the Wing Fortress. In the recent past, Dr. Robotnik used this machine to destroy Sonic in the ship, although was defeated. In the present day, Sonic returned to the Wing Fortress to find that the defenses, incluiding Barrier Eggman, have been left running on automatic. Having defeated the system before, he easily does so again by leaping onto a spiked platform and then hitting the laser cannon with a Spin Attack.
Some time later, Dr. Eggman would recreate Barrier Eggman in the Flying Battery Zone to destroy Sonic and Tails there, but was defeated. A re-built Barrier Eggman would also be used by an Eggbot in an attempt to destroy Knuckles on the ship, but the machine was destroyed again.
When a second player is controlling Tails during the Sonic the Hedgehog 3 & Knuckles version of this boss, the second player can pass through the invisible wall in front of Robotnik.
In Sonic the Hedgehog 2, if Sonic doesn't follow Robotnik downwards and instead jumps over to the pilot seat after beating Barrier Eggman, there is a hidden Extra Lifemonitor to be found.
The laser originally made no sound effects in Sonic the Hedgehog 2, but its Sonic & Knuckles sound effects were added in the 2013 re-release of the game.