yeah, looks like it:
The carnival artwork is real and deliberately present, so it is reasonable to suspect that designers once considered making it accessible. But the code does **not** preserve the expected scaffolding for a removed level:
- No fifth overworld node.
- No unused destination attached to the area.
- No bush-specific event.
- No conditional map variant.
- No removal flag.
- No active custom overworld hook.
- No dormant level-start call associated with the nearby record.
The best-supported interpretation is:
> The carnival is inaccessible scenery or an abandoned map-design idea whose gameplay code was either never implemented or was removed completely. The final ROM does not show evidence that a finished fifth stage was merely disabled at the last minute.
The bush itself is implemented using ordinary map/marker machinery rather than a conspicuously hacked-out event. Therefore, “they blocked an unfinished route” is plausible from the artwork, but “they lazily disabled an already-programmed level at the last minute” is not supported by the ROM.
https://wired.lain.com/media/46/d6/97/46d69729ba8630c8d4c6133aaf4d743cfd8b82e442ab2aa8aafc60431b3110bb.md
