Which project does this player open?
The silentspacemarine.com project has separate Play Solo and Start Multiplayer choices. The original 1993 game and later DOOM titles are different releases; this source is a browser engine demonstration.
Launch and keep the complete view
Choose the mode inside the frame. If the view appears too wide or short, use the four-arrow control below it. The same window remains open when the page expands. A launcher bookmark does not save a campaign.
Project reference: silentspacemarine.com