How to force install a Demo version of game you already own in Steam?
Is it possible to force install the Demo version of a game, for which you already have a full version in Steam?
The reason I want to install a demo is that I want to use it for tests. Like for example, comparing performance with different Vulkan implementations for AMD GPU. And the full game takes significant space on my SSD and I do not want to keep it.
When I go to the game page, and press "install demo", the installer still wants to install the full game (you can see it asks where to install and the required size is big for full version).
There is a solution without creating second account.
Step 1 - find out the appid of the demo version
Demo appid is not the same as full game appid. Visit https://steamdb.info , search your game of interest. In this example I will use FROGUE game, because its demo is just 72 MiB. In search field enter FROGUE, but do not click on the suggested result (it will bring to full version). Just hit enter for your search string. It will bring you to the https://steamdb.info/search/?a=app&q=frogue . You will see two results: one with app type Game (appid 1936990) and another with app type Demo (appid 1941560). You need the demo (1941560).
Step 2 - Run the installation command
Launch steam with console tab enabled:
$ steam-native -console
You can also enable console even if you launched steam without it. For this, run the following command in terminal:
$ steam steam://open/console
Go to Console tab.
app_installcommand, for example:
You will see that downloading started, and then the FROGUE Demo appeared in your library.
Alternatively, use the following command:
It will open a usual installation window, showing you the required disk space and the possibility to choose library folder from dropdown list.