Playmaker is a visual scripting editor that you can install inside Unity3D, the well-known game authoring environment. Within Playmaker, you can create the logic of your interactions visually, without needing to script.
Remembering the power of scripting and the sometimes cumbersome approach of visual programming, I just wonder in how far they manage to let you mix both: that is, use custom scripts (or re-use existing ones) and then combine this or even integrate this with Playmaker. Cause if this is hard to do, you are obliged to do everything inside this tool.
But it is an interesting approach.
Playmaker is not free (about $100) and works in all versions of Unity (free, commercial, iPhone) with Android in preparation. It can be bought from the Unity Assets store.