Lönn

Spec sheet

Purpose

Lönn is a visual level maker and editor for Celeste that can edit map binaries, create maps and rooms, and add objects to rooms.Read 8 Oct 2026 · github.com

Audience

The project is intended for people making maps for Celeste, including mod developers who add compatible plugins.Read 8 Oct 2026 · github.com

Platforms

The installation instructions cover Windows, macOS, and other operating systems using LÖVE 2D version 11.3 or later.Read 7 Oct 2026 · github.com

Security

The opened project README and wiki pages do not state security certifications or compliance claims.Read 7 Oct 2026 · github.com

Support

The project asks users to report bugs and directs questions to the #map_making channel on the Mt. Celeste Climbing Association Discord server.Read 8 Oct 2026 · github.com

License

The README says the source code and most assets are licensed under the MIT license, with exceptions including the logo.Read 8 Oct 2026 · github.com

Development status

The project describes itself as under active development.Read 8 Oct 2026 · github.com

Editing tools

The README documents tools for placing and selecting objects, working with tiles and brushes, editing layers, and changing stylegrounds.Read 8 Oct 2026 · github.com

Game compatibility

Maps created by Lönn can be loaded in the stock game or with Everest, which the project highly recommends.Read 8 Oct 2026 · github.com

Linux distribution

On systems that support AppImage, users can download and run the AppImage release.Read 7 Oct 2026 · github.com

Map editing

It can edit existing map binaries, create new ones, add rooms, and place game objects.Read 7 Oct 2026 · github.com

Map preservation limit

The README says Lönn cannot currently save 100% of original Celeste maps back, estimating support at about 99%, and recommends making backups.Read 8 Oct 2026 · github.com

Other operating systems

For other operating systems, Lönn requires LÖVE 11.3 or later; the README also describes launching an AppImage on systems that support it.Read 8 Oct 2026 · github.com

Plugin documentation

The project wiki provides technical documentation for writing Lönn plugins, including guides for entities and triggers.Read 7 Oct 2026 · github.com

Plugin support

Mod developers need to add compatible Lönn plugins to their mods for them to appear in Lönn.Read 7 Oct 2026 · github.com

Plugins

Mod developers can add compatible Lönn plugins to their mods, and the project wiki documents plugin development.Read 8 Oct 2026 · github.com

Project relationship

Lönn is an unofficial fan project and is not developed by or connected with the Celeste development team.Read 7 Oct 2026 · github.com

Save limitation

The README says Lönn cannot currently save 100% of original Celeste maps back and estimates coverage at about 99%.Read 7 Oct 2026 · github.com

Unofficial project

Lönn is described as an unofficial fan project and says it is not developed by or connected to the Celeste development team.Read 8 Oct 2026 · github.com

Windows and macOS

The installation instructions provide Windows and macOS releases as downloadable ZIP files.Read 8 Oct 2026 · github.com

Where Specifiction places it

• Game Level Editors#19 of 287.3