Before you follow the route
Use the live HUD and the visible result after each step before moving to the next one.
- 01
Confirm the unlock and enter
Do this
Wait for Unlocked: Basement, then use the wooden hatch and stairs beside the house on the Maze or Backyard side; continue down until the HUD changes to Basement and shows its local wave state.
You should see
The HUD reads Basement instead of a neighboring area.
After the Basement unlock, descend the house-side leaf-filled stairs and confirm the HUD changes to Basement.
Source: TheGamerSami - 02
Clear both waves
Do this
Move or collect Leaves in the directions shown by the arrows and red vents, sell when the bag is full, and expect a second wave after the first clears rather than treating the renewed Leaves as a reset bug.
You should see
The final wave reaches 100.0% and the completion UI appears.
- 03
Use the completion exit
Do this
On the House/Easy route described here, the final Basement state is Wave 2/2, Basement 100.0%, and the Basement completion message; after that, enter the opened red vent or duct and continue to the finish guide.
You should see
The route leaves the playable Basement and enters the ending boundary.
Watch the route
Jump to this part of the video.
Relevant section 32:00–36:49