Steam – How to enable Steam overlay while playing Dungeons of Dredmor

Right click on the game name in your library and choose 'view screenshots'.

Steam doesn't know what to do with non-Steam games other than run them, and use the overlay on them (sometimes), so it doesn't show any images or other data about the game in the library.

To add these screenshots (or any others) to your profile page online, select the image in the 'screenshot viewer' using the step above, and then click the 'upload' button on the right.

The Witcher is simply put a horrible "port" that doesn't deserve the name "port".

You could try upgrading the version of Wine it runs on: http://www.insidemacgames.com/forum/index.php?showtopic=43407#entry409385

Now to get technical: The Steam Overlay for Mac is simply a slightly modified and recompiled version of the Windows Overlay. The Overlay tries to detect whether to use a DirectX hook or an OpenGL hook (since both coexist on Windows). The Overlay in this case chooses DirectX, will properly inject but then rely on Windows APIs which are obviously not available, leading to a malfunctioning overlay.

Since you can't tell the overlay what API to hook (Valves detection algorithm does that), this is an issue without a solution you can apply. Whoever ported the game, should take responsibility for this mess and clean it up.