I was in great need to find a game similar to 'Grim Dawn' very much, but noticed 005 Deep Dive is down, so after a little investigation, I encountered this tool:

(EDIT: I no longer recommend the below links, they became UNSECURE with missing SSL website certificates)
http://www.tools.fortressofdoors.com/steamdivingbell/?appid=219990

Simply, change the last appID of GrimDawn in my example (that is 219990) to something else you want (such as 730, which is Counter Strike). So the link will be this:

http://www.tools.fortressofdoors.com/steamdivingbell/?appid=730

You can find AppID of any games via: https://steamdb.info.

If you want to ask anything, don't ask me (I am not the dev), but ask here (I found the tool via this page):
https://www.reddit.com/r/Steam/comments/iit99t/original_version_of_steam_deep_dive_still_working/

I really hope Steam brings Deep Dive back, so we don't need external solutions!

Note: Only problem with the tool is, it is very slow and it requires "waiting" for it to fully load all relevant games (And later if you visit same page again, it loads faster). But if Steam can bring back Deep Dive, it was surely better and faster.