Cave Story+: True Ending Checklist and Sanctuary

The route starts in the Labyrinth, not just with a late-game choice.

1. Cross the upper passage without dropping into the pit where Professor Booster falls. Do not follow the route that gives Booster 0.8.
2. Before fighting the Core, take the Tow Rope from the lower-right side of the room.
3. After the Core battle, use the rope to carry the unconscious Curly into the Waterway.
4. Place her on the bed in the Waterway cabin. Read the bookcase and drain her water; pick her up again before leaving.
5. Obtain Booster 2.0 after returning. At the Plantation, speak to Curly and the nearby person for the memory clue.
6. Speak to Ma Pignon in the room above the village graveyard. Inspect the badge in your inventory, speak again, win the battle and take the mushroom back.
7. Give Curly the mushroom at the Plantation. Speak again after her memory returns and confirm that you receive the Iron Bond.
8. After the Undead Core, enter the Prefab Building and descend through the floor hole into the Sanctuary before jumping outside to finish the escape.

The Counter records your run; it is not itself required to open the Sanctuary.

Choose each landing before spending your remaining boost during a fall.

1. In B1, progress between spike-free landing spots. Collect the Life Capsule, reunite with Curly and carry her.
2. In B2, check the falling blocks before advancing. Do not jump into falling debris while focusing on enemies.
3. In B3, bait the presses first and pass after the route opens. The high chest before Heavy Press holds the final missile expansion.
4. Attack Heavy Press from below while handling side enemies and debris. Move away from the central drop after defeating it.
5. Ballos has multiple phases. Learn their movements and weak points; use healing to survive the next attack rather than judging only your remaining stock.

These are first-clear checkpoints, not a fixed no-damage or speedrun input sequence.