That's a Windows setting; I don't know of any way to override it on the software level, although I'd be very open to adding that if there is such a thing.

--Scratch that--

Turns out it's because Explorer will group programs based on AppID and all games running through dreamseeker.exe will share the same AppID.

There have been programs that do exactly what you want, combine all icons but have a whitelist of excluded programs from combining in the taskbar.

It might be possible but Lummy will have to look into it more, since he'll know more.

I suppose this is a good place to start:

https://blogs.msdn.microsoft.com/oldnewthing/ 20120820-00/?p=6813

Okay, so suppose your application is really a runtime for other applications. What you need to do is assign a different AppID to each of the applications you are hosting. The mechanism for this is up to you. Your applications might explicitly provide a unique ID, or you may be able to infer one. For example, if you are Internet Explorer and your “applications” are pinned Web sites, you can use the URL of the site being pinned as the unique ID.

You then get to take your unique IDs and create AppIDs for them. The format of an AppID is

CompanyName.ProductName.SubProduct.VersionInformation

where the Sub­Product is optional, and the Version­Information is present only if you want different versions of your app to be treated as distinct. (If you want an upgraded version to be a replacement for the old version, then omit the Version­Information so that the old and new versions use the same AppID.)