Screw Mobile

From Sonic Retro

Sonic Retro emblem.svg Sonic the Hedgehog 3
Screw Mobile
Screw Mobile
Game: Sonic the Hedgehog 3
Level: Hydrocity Zone
Hits to defeat: 8

The Screw Mobile (スクリューモービル) is the second boss boss of Sonic the Hedgehog 3, fought at the end of Hydrocity Zone Act 2.


This boss is similar to the Big Shaker mini-boss. As the player enters the arena, the water level drops to the floor and Dr. Eggman/Eggrobo flies in, his craft fitted with an impeller underneath and depth charges at the back. He flies from right to left above the player, where they cannot reach him by jumping, but periodically lowers himself to the water (except for with Knuckles), revving up his impeller. During this time, it is possible to jump and hit the front of his machine, but when he hits the water, the player will want to be as far away as possible.

Upon touching the water, he begins to draw it toward him, while slowly rising. This draws the water into a plume beneath him. If the player does not move to the edge of the screen and hold this direction, they will be drawn into it. Being drawn into this plume will immobilize the player and may cause damage, should they make contact with the impeller. When Eggman releases the water, he moves off and the plume begins to recede gradually. The top of the plume is solid and can be jumped on to reach Eggman's machine, particularly as it drops to the water's surface. The player must be quick though, for the plume will settle and disappear about half a second after it stops on the water. As he flies across the top, he will drop some depth charges which, while damaging in the water, create a explosion that can launch the player high into the air, allowing an attack on Eggman. After eight hits, his craft explodes.


Due to a bug, it is very easy to avoid fighting this boss in Sonic the Hedgehog 3 alone. If the player moves too fast towards the right, the screen will not lock and the player will be able to destroy the Capsule at the end of the level (though Eggman will continue to appear and attack off-screen). However, doing so can cause the transition between Hydrocity Zone and Marble Garden Zone to fail. This was fixed in Sonic the Hedgehog 3 & Knuckles.

This boss also has a bug with Super Sonic in Sonic 3. When the boss is beaten, Sonic does not revert from Super. He can hit the capsule while Super, and stay Super till the Act ends. While Super, the 'Sonic' sign in the text will flash yellow like Super Sonic. This was also fixed in the lock-on title Sonic 3 & Knuckles.

If the player stays in the water long enough without jumping out, the character starts drowning; strangely, jumping out of the water to stop drowning results in changing the boss music to the mini-boss music from Sonic & Knuckles.


Sonic the Hedgehog 3
Sonic3 title.png

Main page (S3&K)
Comparisons (S3&K)

Promotional material
Magazine articles

Hidden content (S3&K)
Bugs (S3&K)
Region coding
Hacking guide