As you know, Flash is disappearing online because modern browsers no longer want to support it. Once browsers stop supporting technology completely, many old Flash games that are still online will be difficult to play
This week, the Internet Archive announced that they have started archiving flash games and animations on their website. These can then be played through a simulator called Ruffle. Ruffle is currently able to play most of the flash stuff made before 2013. More than 1,000 flash items are already stored on the website and more will be archived in the future.
There is already a Flashpoint project, which has already archived tens of thousands of locally downloadable Flash games if you wish now.