LEGO Island Decompilation

About

Lego Island is a 1997 Lego-themed open-world action-adventure game developed and published by Mindscape for Windows, in which players explore the island as one of five minifigure characters; the story follows pizza delivery boy Pepper Roni's efforts to stop an escaped prisoner known as the Brickster. This is a complete decompilation of LEGO Island version 1.1 (English), aiming to match its recompiled code to the original retail machine code as closely as possible. Its ReproBit build reproduces the three original binaries (CONFIG.EXE, ISLE.EXE, and LEGO1.DLL) byte-for-byte using the original Visual C++ 4.2 toolchain, though the project only compiles for 32-bit Windows and is meant as a base for later modification and porting rather than an end-user release on its own.

How it differs from the original

Unlike a typical remake, this project doesn't change or add gameplay — it is a verified, byte-for-byte-accurate recompilation of the exact original code, distinct from the separate isle-portable project that adapts the same codebase for other platforms.

Getting started

It requires an existing copy of LEGO Island version 1.1 (English); the compiled CONFIG.EXE, ISLE.EXE, and LEGO1.DLL are used to replace the matching files in an existing installation. Building it yourself needs either the ReproBit toolchain for an exact reproduction, or CMake with Visual C++ 4.2 for an ordinary development build.

Known issues & limitations

• platform: This is a decompilation for 32-bit Windows only and will not compile for other targets; see isle-portable for cross-platform support.
• The decompilation targets 32-bit Windows and will not compile for other targets.

What you need to run it

Additional notes

Compatibility

Running the game may require separately obtaining d3drm.dll, which stopped shipping with Windows after Windows XP; the project links to a known-good copy.

FAQ

What is LEGO Island Decompilation?

LEGO Island Decompilation is an open-source decompilation of Lego Island. Source code reconstructed from the original game's compiled binary, so the game can be understood, rebuilt and ported. The original game ran on Windows.

Do I need the original game files to run LEGO Island Decompilation?

Yes. The project does not include the original game's assets, so you need your own copy. Original LEGO Island game files are required; place CONFIG.EXE, ISLE.EXE, and LEGO1.DLL in legobin directory.

Which version does this decompilation target?

It targets the English release of version 1.1.

Mentioned in

• What Is a Game Decompilation? Decompilation vs. Recompilation vs. Emulation, Explained