The problem with this is finding/getting the SWFs and compatibility, but newgrounds.com seems to be using this to make old games available, e.g. https://www.newgrounds.com/portal/view/81219
Unfortunately not all games are compatible yet. (Edit: actually, I could only get two games to run - the above-mentioned Fishy and Divine Intervention https://www.newgrounds.com/portal/view/136337; everything else fails)
http://ruffle-rs.s3-website-us-west-1.amazonaws.com/builds/w...