Factorio Forums

The version of factorio released on steam (likely the one available from the factorio website as well) includes a pdb file with the executable. On my windows install, before running the game the entire game is about 400mb of which 100mb is the pdb file. This file is useful for debugging and profiling but offers no use in released software and can be removed without consequence. Additional as this file will change each time the exe is modified it would mean potential greatly increasing update sizes as well as the initial install.

The file exists so the stack traces produced if the game crashes are human readable. It's intended to be there.