I have created a small unity game (about 10 classes). Then I have decompiled it with dnSpy. Fixed a few issues and created a VS Project.
My problem is that Assembly-CSharp.dll references some unity dlls. But curiosly everithing workes except UnityEngine.UI. If I reference UnityEngine.UI, the IntelliSence says everything is ok, but if I compile it, all classes in UnityEngine.UI where not found.