Death Egg Mark III is the final zone of Sonic the Hedgehog 4: Episode 4. It looks simillar to the original Death Egg, but with an Egg Destructo Laser at the bottom, which is Eggman's version of the Eclipse Cannon.
Sliver Sonic's Beating
In the first act, Sonic, Tails, Knuckles, and Shadow are rushing onto the Death Egg Mk. III in 2 teams. The first part of the act is a platforming section filled with Badniks from all over the game. The second part (marked by a check point) is a Sonic 2 like battle with Sliver Sonic. Once you beat Sliver Sonic, the third part begins. In the third and final part of the act, Eggman hops in his new Egg Claw. The claw will strike where you see a red X. When you defeat the Egg Claw, Eggman will fly to Act 2.
The second act is a pre-final boss act. Remember how Eggman went onto this act? Well he came prepared. You'll be battling the Egg Armor, a Death Egg Robot like robot with a suit of armor. This boss is a little bit harder then the Egg Claw, but you'll need to hit Eggman's cockpit 3 times, and then he'll say "Time to upgrade!". You'll now face the Egg Armor Z. You'll need to hit the cockpit 10 times to win. Eggman will then get ready for your final battle with him. He'll launch you out into space. If you've collect 5 of the Chaos Emeralds, you'll battle only the final boss. However, if you get all 7, you'll be able to go into Act 3 and the bonus Act 4.
After being launched into space, Shadow Chaos Controls you and the others to the Space Deck, the final boss area. You'll see the final boss of this game is the Egg Destructo Laser Mech. This act is spilt into 2 parts so you can battle him twice. At the end of each act, if you have 50 or more rings, you'll get a Chaos Emerald. The first part requires you to hit Eggman's cockpit 20 times before he blasts you with his laser. The second part requires you to dodge Eggman's attacks and then get the arm to hit 23 bombs. Eggman will fall into space after Act 3, but it's not over if you have all 7 Chaos Emeralds.