---not relevant, you may delete it---

You can just open support ticket to Add Game to List or you can drop them here.

Hmm, it's great if there is such possibility!
Thank you for your attention and for your comment.

Yes, I've seen that there is a link to steam store pages and after a little testing I do realize that the function I was thinking about exists already. Therefore, yes, the problem was precisely in the game that has been on the list a year ago and now it is not there. I will try to use the opportunity of support ticket or take advantage of the thread that was recommended above. Thanks again!