Dr. Eggman (Sonic the Hedgehog Triple Trouble boss)

Atomic Destroyer Zone, the final level of Sonic Triple Trouble, involves four consecutive bosses, with a guest appearence by the cowardly Nack the Weasel in the middle.

Four bosses, you say?

Although their race / battle in Stardust Speedway Zone during Sonic CD is much more well known, Sonic and Metallix clashed once again inside the Doctor's titanic superweapon. After a brief race on rocket-shoes (or just flying, if you're playing as Tails), Metal attacks, flying back and forth across the screen and periodicly swooping along the floor with his electric shield. Simply dodge the robot while he's charged up, and land hits when the shield depletes.

With Metal Sonic knocked out of the fight, Nack the Weasel briefly shows his face. Presumably in Atomic Destroyer to steal the final Emerald (the one in Eggman's posession), Nack turns and flees on catching sight of Robotnik's armoured pogo-mech; leaving you to face the Doctor one-on-one. This machine dosn't put up much of a fight, and explodes after a mere 10 hits.

But the fat man's not nearly done yet. Eggman proceeds to bring out a significantly more dangerous contraption, that spews jets of flame all over the place. Even after you disable this incinerating weapon, Robotnik launches a series of electric and energy-ball attacks, while the broken, sparking conduits of his flame-gun make attacking hazardous. This section requires 17 hits for victory.

And then there's more. The final part of the boss sees Eggman's pod shift up and down between the two ends of a electricity chamber. Energy bolts fire from cannons above you, and the entire room is periodicly shot through with lightning. The only way for Sonic or Tails to dodge is to hop inside whichever chute Eggman isn't occupying at the time.

Ending

Finally, after four bosses in a row, Eggman is out of defences. The obese scientist flees to a floating platform, but drops the final, yellow Emerald during his hasty retreat. Sonic proceeds onwards to find an imprisoned Knuckles, presumably captured by Eggman after the echidna's defeat at Tidal Plant Zone. After destroying the energy cage, the Guardian concedes a thankful handshake, before the two of you flee the base.

If all 6 Chaos Emeralds are already collected, the credits will roll. If any of them are missing, a cutscene will play instead, with Fang laughing at the player's character. He trips and spills however many Chaos Emeralds were missed, and then the text "Try Again" appears. The music for this ending is a pitched-down version of the "Try Again" theme from Sonic Chaos.