Enjoying the game so far, picked it up yesterday (...just missing out on the sale...) from GoG. One of the pain points seems to be that the GoG version doesn't work with the Steam overlay.

Anyone know how to make this work?

Are you honest with your question?

Steamversions of Games are modified to need Steam as a Client/DRM and to use the communityfeatures Steam offers.

GOGversions of Games are modified to be DRM/Clientfree.

So..no chance to make the GOG-version working with STEAM.

it is a pretty honest actually... the Steam overlay function is not directly tied to Steamworks or Steam DRM and such, it is simply a feature of the client software; as long as the game is launched via Steam, and is rendered with a supported graphical engine, it works.

That means that you can take a GOG game, or any .EXE that you like for that matter, add a shotcut in the Steam client, and after launch you can access Steam overlay and its features (chat, integrated browser and so on)...
It does not work 100% of the times, one know limitation is , for example, with games that start with a launcher before switching the main EXE, but it usually do

I've personally tried it with Legend of Grimrock, GOG version, and OOlite, the open source Elite remake, and it works perfectly

Edit:
found a more specific quote
"The Game Overlay will work with third-party non-Steam games which you have added to Steam. The basic requirement is that the game uses Direct3D 7, Direct3D 8, Direct3D 9, Direct3D 10, or OpenGL for rendering. Some 2D games which use DDraw or software based rendering methods are not supported (ex/ Diablo)."

Yep :) It's a standard feature of Steam, and it's my default mechanism for launching games, GoG ones included, so that I can get things like a browser overlay and my Steam friends list.

To DF1871, your comment implies that only Steam games work with the overlay, which just isn't true. Games that are supplied by Steam don't have a magic switch that disables them - I can think of at least one (Might and Magic X: Legacy) that I picked up from Amazon (...sort of direct Uplay) and despite it being on Steam the non-Steam version works fine with the overlay when launched from Steam.

Back to my "honest" question, does anyone know why this doesn't work? I thought I'd try here first because surely someone else has bumped their knee into this one. It doesn't matter whether I run it in windowed or fullscreen mode.

Well..i apalogize for my nescience.

Before i abondend Steam completly i made the experience that Steam, to use your words, isn't a magic switch but magic chain to tie games, Pc's and bit by bit..the user behind the monitor ;)..forcing his way deeper every day...so i couldn't imagine that it would support any of his features to a non-Steam-game...but i didn't take into account that they might use seduction and deception too ;).

But...to be honest...i really apologize because i let my own negative attitude about Steam dictacte an anwser without knowing for sure.

Yeah, all good :) I started disliking buying games from Steam about the same time they started jacking up my price because I wasn't in the USA. GoG seem much more equitable, and have a healthier approach to DRM (that is, they don't do it).

Still, Steam have an advantage in that all my friends seem to use it, so it's sort of the defacto chat system I get to use these days :( Oh, for the GoG Downloader to evolve into something a bit more advanced :)

Well...many people use it..because the games the want to play are chained to it.

Some of my friends bought a additional X-Box to avoid Steam..abondening the PC as a "gaming-machine"
but most wish to stay with a PC..and a Pc+new games=forced to use Steam.

For those of you watching at home, there is a workaround that seems to be ok so far: the GoG version runs in admin mode, so disabling run-as-admin fixes the issue with the Steam overlay. No clue why the two versions run differently, but a couple fights on from trying this fix suggests it doesn't really need the admin rights to function.

I can't remember if the Steam demo version ran with admin rights or not, it's too long ago now.

Afaik, almost all of them only offer steam keys. I know only one game has both and thas only for those who purchased before dev decided to go steam only. The non steam version has game breaking bugs and for what ever reason dev decided its too much work to provide patch to non steam version and instead gave (after over year of complaints) all who bought non steam version steam keys (that is entirely useless for me at least). Unfortunately it's more and more common for games to be steam only. There are plenty of games on steam I and many others would buy if non steam version was available but there isn't so we have to do without.

GOG is DRM-free (and thus Steam free) digital distribution service and that's how the customer base likes it. If you don't like it buy your games elsewhere. It's not like there is shortage of steam key resellers.

^This.

In regards to "moving around quite a bit" I never have quite understood that. I guess there are those out there that feel the need to install and play their games on every computer they encounter. Anyway, that is why I have external HDs that take care of my moving around if need be. I have no qualms doing things the "hard way" which is really not all that hard. But that is just me, and not having to toss a play disc in my CD Drive is convenient enough. I guess I'm just not hardcore enough and old school.

Hey, not sure if anybody's interested at this point, and maybe this won't necessarily help anyone anymore, but here's how I managed to play The Witcher 3 with a steam overlay and steam controller WHILE having GOG Galaxy track the time and achievements (exactly as it would if I had opened it from the G.Client).

1 - My Steam runs on admin privileges - occasionally some issues are fixed this way. My GOG Galaxy runs without admin privileges.

2 - My GOG Galaxy has its overlay TURNED OFF.

3 - Add a Non-Steam Game to your Steam Library and find the .exe file in your game's install folder. After it's added you can rename the shortcut to anything you'd like, including the official Steam/GOG name by copy/pasting it into the properties.

4 - Run the Steam version with the layout options all working.

5 - Before (or even after) the game starts, go to your GOG Client and find your game on it. Launch it.

6 - An informative message will appear saying something along the lines of "The game is already running". Click OK.

And you're done. GOG Galaxy will think that the game started twice for some reason and start tracking as if nothing happened. If you're quick enough, you can inform Galaxy of the running game before it even launches on your screen (though it's entirely NOT NECESSARY. At most you'll lose 5 seconds Alt+TABbing to click the Launch button).

The next time the game shuts down, Galaxy will sync all the saved data, including time spent playing and all the achievements. The Steam Controller runs just fine with its own Overlay that you can use to tweak the controls, remap buttons, add functions, etc.

Disclaimer: You can sync the save files to the GOG cloud any time you want, but the time spent playing is done 'in the moment'. So if you forget to launch the game through Galaxy and play the game for 3 hours through Steam, Galaxy will never know, and there's no way of adding 3 hours to the game (unless you ask someone from GOG to correct it manually).

It's not a big issue, but sometimes people forget and that might cause them to lose some statistical data like 'time spent playing'. The game runs smoothly regardless.