Do I need the original game files to run Onegai Monsters Decompilation?

Yes. The project does not include the original game's assets, so you need your own copy.

Onegai Monsters Decompilation

DecompilationSporadic

Source code reconstructed from the original game's compiled binary, so the game can be understood, rebuilt and ported.

A repository exploring a decompilation of Onegai Monsters. The author calls it super minimal and says it likely won't become a full decomp project.

Then place a base ROM in the project root and run the setup, extract and build make targets.

The author says they mainly wanted to see what was in the game.

Original game files required. The project ships code only; you provide your own copy of the game.

What is Onegai Monsters Decompilation?: Onegai Monsters Decompilation is an open-source decompilation. Source code reconstructed from the original game's compiled binary, so the game can be understood, rebuilt and ported.
Do I need the original game files to run Onegai Monsters Decompilation?: Yes. The project does not include the original game's assets, so you need your own copy.