I've spend almost all the last year developing something I had in my mind for a long times.
I play a lot of old retail and GoG games, I share my PC with my brother and also I like to keep my savedata safe. When Steam Cloud deleted my 40 hours MGS V savedata, I've decided to fight back creating...comPLAY!
I've tried to explain every features in the shortest possible time on the official webste : http://www.complay.info
If you can't or don't want to use ONLY Steam Cloud, if you have some games that you want to "cloud-ize", you want to play the same games with a brother or an housemate or one of the tons of extra little things I've accomplished with my free tool...
...it worth a try! It has a lot of unseen features, and is exactly what I wanted to have but it didn't existed until I've created it himself. I've created it for myself, and IMHO is a seal of quality :)
Also, every game inside comPLAY is hotlinked on PCGW because I think it's one of the best resource in the whole pc gaming from many years to now, so open the game's PCGW page is a question of a single click.
Its free to use and download, and also you can review the code,and I would therefore be very curious to listen on any opinions:)