I installed Eclipse and a project based on Sample.java worked out of the box for me on both Windows 7 and Windows 8.1, using jdk-8u5 64-bit.
Looking for ways to reproduce the error, I then uninstalled the Microsoft Visual C++ 2013 x64 Redistributable. At that point I was able to get x64\LeapJava.dll: Can't find dependent libraries. This represents at least one bug in our Java binding. Leap.dll isn't properly searching its "loader path" as LeapJava.dll does. When I copy msvcr120.dll and msvcp120.dll to C:\Windows\System32, it then works again.
Could you go to Programs and Features and check if you have Microsoft Visual C++ 2013 Redistributable (x64) installed? If not, you can download it from the web and install.
If this turns out to be the underlying problem, then it makes sense that Dependency Walker didn't help. That tool searches for libraries in the main DLL's folder so it wouldn't catch such a path-crossing issue. And if this doesn't solve the problem, I'll have to think of a next troubleshooting step that doen't involve Dependency Walker.