You can't have a unified opinion here. There are some pretty good public game codebases (Penumbra/HPL, Quake I/II/III, Doom I/III), there are some okay ones (R

You can't have a unified opinion here. There are some pretty good public game codebases (Penumbra/HPL, Quake I/II/III, Doom I/III), there are some okay ones (RedAlert), there are also pretty awful ones (Duke3D, Descent). Note that this seems to be completely independent from whether the game is good or not!