# Castle Excellent: shared-source NES reconstruction with Castlequest

> Reconstructs Castle Excellent for Famicom and Castlequest for NES from shared ca65 assembly source. The build extracts private assets from users' ROMs and compares each revision byte for byte; MAME attract-mode checks cover selected behavior after code relocation.

- Type: Case study
- Targets: Game
- Category: Independent reconstruction cases
- Relationship: Independent reconstruction project
- Sources reviewed: 2026-11-06
- Added to the catalog: 2026-11-09
- Original resource: <https://github.com/RetrolariumLab/castle_excellent_src>
- Primary source: <https://github.com/RetrolariumLab/castle_excellent_src/blob/7ff7ff6739518e7a108368d74456f0dc689b7b78/README.md>
- Catalog page: <https://awesomerea.org/resources/castle-excellent-castlequest-reconstruction-case/>
- Record JSON: <https://awesomerea.org/resources/castle-excellent-castlequest-reconstruction-case/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/castle-excellent-castlequest-reconstruction-case/index.md)

## Requirements & limits

- **Prerequisites:** Requires Python 3.11+, GNU Make, Retrolarium Kit, and a user-supplied Castle Excellent ROM; Castlequest verification needs its US ROM as well.
- **Testing evidence:** Attract-mode checks cover the title-room demo path, without room changes, deaths, lifts, or Witch behavior.
- **License:** No licence file in the repository.

## Primary sources

1. <https://github.com/RetrolariumLab/castle_excellent_src/blob/7ff7ff6739518e7a108368d74456f0dc689b7b78/README.md>
2. <https://github.com/RetrolariumLab/castle_excellent_src/blob/7ff7ff6739518e7a108368d74456f0dc689b7b78/docs/architecture.md>

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## About this entry

The description was reviewed against primary sources.
Original editorial content: MIT. Linked projects, papers and assets retain their own rights and licenses.