Silver Castle Zone is the fifth and final Zone of Sonic Blast. As with other Zones in this game, Silver Castle consists of two standard Acts followed by a shorter third Act which contains the Zone's boss.
Silver Castle is another one of the many mechanical fortresses constructed by Dr. Eggman, with the exterior resembling the Death Egg as seen in the ending of Sonic Blast, and its interiors resembling other industrial levels like Scrap Brain Zone from Sonic the Hedgehog, built as part of the evil genius' bid to take the Chaos Emeralds of South Island.
As the final Zone of the game, Eggman has placed many devices and hazards around Silver Castle, such as numerous teleporters that lead to different areas around the fortress. Some of the teleporters will be inactive, and must be powered on by standing on rotating platforms to charge up power. At specific parts of the Zone are advancing spike walls that the player must run away from to avoid getting crushed. Other hazards include electrical fields that will zap the player, and sticky yellow floors that slow the player down.
||This chrome-plated castle is filled with Dr. Robotnik's most up-to-date mechanical monstrosities. Corkscrews, cannon-firing robots and steel spikes are just some of the dangers. Keep track of where transporters send you - things get confusing mighty quick!
— Sonic Blast US manual
||Egg Saucer — Razor-belted Badnik that dashes through the air.
||Egg Sentry — Cannon-toting Badnik that shoots projectiles.
||Egg Pogo — Pogo-mounted Badnik that bounces about.