The unpatched release of Version 0.10 contains unused data for an event on Mars called "階段←↓". Re-enabling this event opens an alternate, invisible entrance to the Martian underground, to the left of the hole that leads to it in the final game; however, the map's collision data prevents Madotsuki from actually using it without the aid of further cheats.

Furthermore, the game contains unused graphics for a stairway that matches the visuals of the Martian surface, and the Martian underground features several flights of stairs at the beginning. This indicates that the underground was originally meant to be accessed via the unused stairway rather than needing Madotsuki to activate the Midget effect, with the summit's layout being changed concurrently with the altered entrance. The Yumesyuusei Patch and all releases based on it (including the official English release) remove the data for 階段←↓, though the unused stair tiles are unaffected.

Additionally, the game's code contains tiles for doors on the walls of the Martian underground, indicating that the sub-area was originally planned to feature multiple rooms rather than just one. This, combined with the unused alternate entrance, implies that Kikiyama had to leave Mars incomplete for unknown reasons, polishing up what was already completed late into Version 0.10's development.