Eternal DOOM I-III (DOOM II WAD) - Not (really) a Full Playthrough (w/ commentary)
This is a level pack that was being developed by Team Eternal before it was expanded by TeamTNT. It was originally released as a 13-level WAD with the last being a credits map before receiving an upgrade (Eternal II) which adds more levels, turning it into a fully-fledged megawad, with Eternal III adding a few more. The full package can be known as Eternal I-III or just Eternal III.
I've managed to play through all the Eternal I levels in this video, but was just about ready to give up by the time I reached the Eternal II levels. All this complication and no clear signs on where to go next just made me ready to skip to the end. I was mainly looking forward to playing the bonus levels which were included in their own WAD files (played at the end of the video). Other than that, I recommend you play this only if you want to get stuck in areas with no where else to go.