Shiny Egg review
A free desktop toolkit for editing Yoshi’s Island levels and assets across three operating systems.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Shiny Egg is a free desktop editor for modifying levels and other content in Yoshi’s Island for SNES. It is aimed at solo ROM hackers focused on that game, rather than people looking for a general-purpose editor across multiple titles. The application runs on Windows, Linux, and macOS, and is open source. Users need to provide an unedited Yoshi’s Island USA 1.0 ROM; the tool does not include a game ROM.
Its scope extends beyond level layout. Shiny Egg edits tiles and sprites with copy/paste, undo, and multiselect, and supports palette and level-header editing with live previews. It also handles world maps and strings, offers arbitrary spawn positions for testing levels, and can move levels into free ROM space using memory management tools. Graphics import and export covers PNG, Aseprite, M1TE, and YYCHR; audio workflows use AMK- and AMY-style MML files. These features make it a fit for projects that need several kinds of Yoshi’s Island content editing in one desktop tool, rather than a narrowly focused level-only workflow.
Patch creation and emulator integration are useful parts of the workflow: the editor creates ASM and binary patches designed to resist address drift, imports existing patches, and works with BizHawk and Mesen. It can also import existing ROM hacks and levels from the GBA version. However, its game-specific scope rules it out for users who want to edit other games, and the project is identified as alpha and a work in progress. Choose it if Yoshi’s Island SNES editing is the goal and an alpha tool fits your needs; choose a broader editor if you need cross-game coverage or a more established project.
Shiny Egg pros and cons
- Where it wins
- Edits levels, tiles, sprites, palettes, world maps, and strings
- Supports graphics and audio import/export workflows
- Creates ASM and binary patches and integrates with BizHawk and Mesen
- Where it doesn't
- Focused specifically on Yoshi’s Island for SNES
- Requires a legally owned Yoshi’s Island USA 1.0 ROM
- Alpha work in progress may not suit users seeking a mature editor
Shiny Egg fact sheet, pricing and score →
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