G3M

G3M is a free, open-source desktop manager for mods in GameMaker titles. It is best suited to players and mod creators who want profiles, patching tools, and several installation methods across Windows, Linux, and macOS. Its focused game catalog and unusually deep editing workflow make it a specialist choice rather than a universal mod manager.

Overview

G3M brings mod discovery, installation, organization, editing, and launching into one application. Built-in entries cover DELTARUNE, DELTARUNE Demo, UNDERTALE, UNDERTALE Yellow, Pizza Tower, Sugary Spire, and FRICKBEARS3. The in-app Game Manager can add custom GameMaker games, so the fixed catalog is not an absolute boundary, but the software remains centered on GameMaker rather than games across every engine.

It integrates with GameBanana and accepts mods from external URLs, local archives, and one-click install links. That combination suits users who alternate between browsing a catalog and managing files obtained from elsewhere.

Key features

Profiles and conflict control

Multiple library profiles keep active mod selections and profile-scoped settings separate. This is useful when maintaining different playthroughs, testing combinations, or sharing a computer. Conflict detection flags overlapping changes before they become a harder-to-diagnose launch problem, although it does not remove the need to decide which mod should take priority.

Editing and patching

The Mod Editor combines patches, file replacements, and archive contents, and can export a finished mod for sharing. Separate tools create and apply patches, merge patch sets, compare files, export diff reports, and convert mods between supported formats. Those capabilities give creators and curators a practical workflow for refining and distributing changes; players who only install finished mods may find this depth unnecessary.

Launching and extensions

Games can launch directly or through Steam where available. On Linux, PortProton can be used for compatible Windows games, extending the practical reach beyond native builds. Normal launch mode restores game files after the game closes, an important safeguard when experimenting with replacements.

The Catalog adds plugins and themes. DR Save Manager targets DELTARUNE saves, while Custom Saves Folders lets users choose save locations. Installed or imported themes and language packs for English, Russian, Spanish, Korean, Japanese, Simplified Chinese, and Traditional Chinese make the interface more adaptable without changing its core GameMaker focus.

Pricing

There is no paid tier, trial period, seat quota, or renewal term. The free GPL-3.0 distribution fits anyone who wants the complete desktop feature set without a subscription. The trade-off is project support rather than commercial service guarantees: security fixes are best-effort for the main branch and latest release, while older releases are unsupported.

Platforms

G3M runs on Linux, macOS, and Windows. Release downloads target x86_64 and ARM64 computers, giving current desktop hardware a straightforward path. Linux users also have the PortProton route for compatible Windows games, while Steam launching is available where supported.

Who it's for

Choose G3M if your library is mainly GameMaker games and you want profile switching, conflict visibility, built-in source access, and tools for making or sharing patches. It is especially compelling for mod authors and maintainers who need comparisons, diff reports, format conversion, and combined replacements. It is less suitable if you need a broad manager for unrelated engines or depend on long-term security maintenance for old versions.

Pros and cons

• Pros: Free GPL-3.0 distribution with no usage limits stated; works on Windows, Linux, and macOS; supports GameBanana, URLs, archives, and one-click installs; profiles and conflict detection make larger mod setups easier to control; editing and patch tools support creation as well as installation; file restoration after launch reduces the risk of leaving a game altered.
• Cons: The built-in catalog is concentrated on seven GameMaker games; custom-game support still requires adding entries yourself; the advanced editor may be more than a casual installer needs; older releases do not receive security support.

Alternatives

Browse the Game Mod Managers category for a wider comparison. Modrinth is the better pick for a freemium, web-and-desktop ecosystem with a creator-support subscription and API access. CurseForge suits readers focused on Minecraft mods and modpacks through its web catalog and free plan. Vortex is a free, open-source Windows extension-based manager from Nexus Mods. Modrix offers a free, open-source option across extension, Linux, macOS, and Windows. CKAN is a free, MIT-licensed manager for its supported ecosystem. Irony Mod Manager targets supported Paradox games. RimModManager is a free, open-source choice with no stated price or usage limits. FlairX Mod Manager is a free Windows-only open-source alternative.

Verdict

G3M is the right recommendation for GameMaker players and creators who value profiles, conflict detection, flexible installs, and serious patch and comparison tools at no cost. Look elsewhere for a manager built around other engines, a broader general-purpose catalog, or supported security maintenance on older releases.