There is one way and one way only which requires you to own this game on steam.
　

• Enter your browser and paste into the blank url steam://open/console
  
• This will open a hidden tab in your steam client, the "console"
  
• Paste this command into the console: download_depot 1229490 1229491 2325647322852928543

　
This will begin downloading an old version of ultrakill. It will function like a regular download, although with a few key differences.
　

• The download is categorised entirely different from a game - you will need to manually start the exe file outside of Steam.
  
• It will still add playtime to your total time spent in game
  
• The download happens entirely in the background, although Steam will still show you what network the download is using.

To create shortcuts, we will need to find the exe file to run the old ultrakill. I recommend naming it something other than the default exe name.

The depot's location you downloaded should be stored at C:\Program Files (x86)\Steam\steamapps\content\app_1229490\depot_1229491, assuming Steam was downloaded in the default directory.

From here you can make a shortcut to either that directory or the exe, by minimizing file explorer and dragging the files over to your desktop.

If you want the steam overlay, you can go to the steam app > Games > Add a non-steam game to my library. Then browse and copy paste the depot's directory and add the exe.

While Patch 11B has nearly none of the imperfect features of modern ultrakill, Patch 11B lacks mod support, many changes and new levels.

This version goes back quite far, as it was the last version before the srs cannon and P-2 was created.

There are also many small qol features missing (no muffle option on underwater music, no sfx slider, etc) and the meta is almost entirely different compared to modern ultrakill's.