The latest update has brought changes to demos; from now on, demos can have their own review pages. I have converted all old demos to have their own pages. The link to the demo can be found on the main product page; unfortunately, the "Learn more about this demo" link is not very visible and looks like regular text (it's located next to the "Download" button).
I mainly provide the demo so you can check if you like the game and to see if there are any technical issues. However, I've noticed that more and more players want to get to know the game simply (understand the story, plot, etc.), so it's nice that you can review the demo and leave feedback about it.
You can find all my demos here: https://store.steampowered.com/search/?supportedlang=polish&category1=10&developer=Airem&ndl=1.
PS. The Airhack demo page is currently under review (and will be up in a few days): https://store.steampowered.com/app/2753210/Airhack_Demo/