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Part 21
Sonic the Hedgehog

Part 21

Sonic the Hedgehog Part 21 walkthrough covers White Acropolis, Egg Genesis boss, Radical Train, and more. Learn how to beat bosses and get S-ranks.

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Sonic the Hedgehog Part 21 walkthrough covers White Acropolis, Egg Genesis boss, Radical Train, and more. Learn how to beat bosses and get S-ranks.

Walkthrough
  1. 1
    Head to White Acropolis for Act 4: Infiltrate Dr. Eggman's Base! (Medium difficulty, Eggman Robots).
  2. 2
    In White Acropolis, throw rocks at searchlights to break them, freeing springs and reducing robot spawns.
  3. 3
    For the goal ring in the last section, stick to the left, glide across a gap, go through a half-pipe with red arrows, and levitate over a hole to reach the higher area.
  4. 4
    For an S-rank, kill many enemies and keep your Rings.
  5. 5
    Prepare for BOSS 3: EGG GENESIS (Easy-medium difficulty).
  6. 6
    To beat Egg Genesis, throw junk at its center, especially when it's low and its arms aren't protecting it. Boxes are on the outskirts. Capture and return its missiles. It fires missiles and a homing laser; ground enemies interfere.
  7. 7
    After the enemy hit bar reaches zero, run away from the ship to avoid crashing.
  8. 8
    For an S-rank on Egg Genesis, catch and throw many missiles quickly, throw boxes between missiles, and hit the center instead of searchlights for more damage. Damaging it during laser lock-on can cancel its attack and cause parts to fall off. Collect Rings around the edge when its health is zero and it's crashing. An S-rank was achieved in under 1 minute 30 seconds with 10 Rings.
  9. 9
    Undertake TOWN MISSION #12: Defeat the Pursuers and Escort Elise! (Amy, Easy difficulty).
  10. 10
    Defeat all enemies in this mission.
  11. 11
    For an S-rank on this mission, use stun boxes first, destroy barricades for extra points, and collect all Rings. Avoid using springs to drop spiky balls or getting a 1up from the roof to save time.
  12. 12
    Proceed to NEW CITY: IN MIDDLE OF TOWN FACING TRAIN STATION.
  13. 13
    The mission Head for the station! requires you to buy the Heart of Wind for 1000 Rings from the shop to continue the story.
  14. 14
    The train station is near the entrance to White Acropolis.
  15. 15
    Upon approaching the Train Station after buying the Heart of Wind, a Town Mission will start.
  16. 16
    Undertake TOWN MISSION #11: Get into the station! (Easy difficulty).
  17. 17
    Hide from guards behind barrels to enter the Train Station.
  18. 18
    For an S-rank, run to the right side; hiding is not essential. Sneak behind the guard in the corner and the pacing guard in front of the station.
  19. 19
    Proceed to Act 5: RADICAL TRAIN (normal, puzzle, Medium difficulty, Eggman Robots).
  20. 20
    The mission is Find Sonic!
  21. 21
    Use the scales in pairs: putting weight on one makes the other go up. Use telekinesis (kenesis) to add or remove weights. Find the switch near the scales to reset them.
  22. 22
    For the first pair of scales, take the weight off.
  23. 23
    For the second pair, stand on the scale next to the desired ledge while holding three boxes, then put the boxes on the other scale to raise it.
  24. 24
    For the next two pairs of scales, take the weights off.
  25. 25
    If you have trouble with conveyor belts, run on the small ledge between them.
  26. 26
    To break down doors, throw items at them until they break.
  27. 27
    For an S-rank, grab many Rings and destroy many enemies.
  28. 28
    Prepare for BOSS 4: SHADOW THE HEDGEHOG (Medium difficulty).
  29. 29
    To beat Shadow, throw junk at him, especially in the center. Avoid picking him up when stunned and staying close, as he will create a Tornado. Moving away after picking him up is fine. He uses Chaos Boost and enhanced abilities later.
  30. 30
    For an S-rank, throw barrels at him in the center. Grab him when stunned and grab barrels, which regenerate quickly. Collect Rings. Barrels thrown at the center do more damage than hitting the searchlights.
  31. 31
    Proceed to Act 6: AQUATIC BASE (Support Character, Hard difficulty, Monsters).
  32. 32
    The mission is Follow Iblis!
  33. 33
    Activate cylinder-shaped devices by pressing the Attack button when standing next to them; they glow blue and kill nearby enemies.
Tips
  • Throw rocks at searchlights in White Acropolis to break them, freeing springs and reducing robot spawns.
  • For the goal ring in White Acropolis's last section, stick left, glide across a gap, go through a half-pipe with red arrows, and levitate over a hole.
  • For the Radical Train scale puzzle, use telekinesis to adjust weights. Reset scales with a nearby switch. For the second pair, use boxes to raise the scale next to the ledge.
  • If you have trouble with conveyor belts in Radical Train, run on the ledge between them.
  • Throw items at doors in Radical Train to break them.
  • To beat Egg Genesis, throw junk at its center when its arms aren't protecting it. Capture and return missiles.
  • For an S-rank on Egg Genesis, catch many missiles, throw boxes, and hit the center. Damaging it during laser lock-on can cancel its attack.
  • For the Defeat the Pursuers and Escort Elise! mission, use stun boxes first and destroy barricades for extra points.
  • To get the Heart of Wind in New City, buy it for 1000 Rings from the shop.
  • In Town Mission #11, hide behind barrels or sneak behind guards to enter the station.
  • To beat Shadow the Hedgehog, throw junk at him. Avoid picking him up when stunned and staying close.
  • For an S-rank on Shadow, throw barrels at him, grab him when stunned, and collect regenerating barrels and Rings.
  • In Aquatic Base, activate cylinder-shaped devices by pressing Attack to kill nearby enemies.

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