Get Penumbra Collection for close to nothing!

[bajatar]

I was wondering what I would need to do when I buy my new computer. And I did not like the idea of loosing the game if the service is shut down for whatever reason (this is not only for Amnesia but for download versions in general).

There are different services that handle things differently. From my experience:

Services like Gamersgate, Direct2Drive, GoG and games sold directly by developers (e.g. FrictionalGames), simply let you download a regular installer - which would otherwise be on a CD - and you use this to install the game. Those installers are run-of-the-mill, not bound to your computer and can be backed up trivially (burn them on a CD/DVD or put them on a backup harddrive). There's nothing that binds you to these services so for all you care, they can go bankrupt the next day (not that I'd wish it to any of them).

Other services like Impulse and Steam have clients that handle installation. Backup can be a bit more complex. Steam is completely locked down and you are at their mercy (if they'll be gone, your games will be gone). Impulse is more open, in that you can usually simply zip the installed game and make a backup.

Unfortunately it's up to the publisher whether they want to add an online-activation DRM system on top of that (which makes you dependent on them to be able to install the game and usually cause the installation - not the installer - to be bound to your system). Those DRMs are in retail bought games too, so it's not a download-only issue.