Doom 3 [xbox Classic] -

Character models and environments were simplified, but high-resolution normal maps were used to keep the "bumpy," detailed look of the PC version.

The large levels from the PC were broken into smaller chunks with more frequent loading screens to manage memory. DOOM 3 [Xbox Classic]

The Xbox Classic version isn't just a "lite" port; it actually has features the original PC version lacked: Character models and environments were simplified