Thanks for giving it a shot Simon. Sorry it's not working for you out of the box.
Any chance I can get a hold of the executable you are using? If not, could you possibly generate a .DMP that I could look at over here? I've been testing with various binaries, including Handmade Hero, though on a Windows 10 machine.
I just tried the debugger, and it seems to work just fine. Until there is support for expressions in the watch window I probably won't be able to actively use it. However, I am excited about seeing the project develop!
After many hours of setting up a Windows 7 VM and about two minutes of debugging :) I found the crash that showed up on Windows 7 (and was unfortunately suppressed on Windows 10).
Turns out that in one of the calls to ReadFile I was passing in NULL for the 'lpNumberOfBytesRead' parameter. Clear as day in the documentation it states: "This parameter can be NULL only when the lpOverlapped parameter is not NULL".
The fix will show up in the next release. I'm expecting sometime later tomorrow.