Self-Hosted Steam / Game Manager

I've been trying to find something like this for some time. There are self-hosted alternatives to Spotify, Netflix and lots of other services. But surprisingly I haven't found any alternative to Steam. The closest thing I've found is GameVault but it's not open source, the client only runs on Windows and I find it really limited.

The idea would be to have your games (without drm) stored on your server, then you could easily download them from any computer and play the games. Maybe it could even track playtime or achievements, and even have a federated friends system.

Do you know of any viable alternative that currently exists? If not, do you know why there isn't any software for this purpose?

Btw, I'm up to building this software if it doesn't exist yet.

https://redd.it/1x0jt8t
@r_SelfHosted