Are you playing the web version? That was a really last minute build that still may have issues (albeit so does everything - it's a work in progress)
What resolution are you playing it at? It's possible that the game window isn't running in its 1440x1080 set size and that may be causing issues (we had basically no play testing time and this is still very much a work in progress but that build does have ok hit detection in windowed mode). The cursor should change icon to show the clickable object type (ie doors should have a open door icon cursor and people should have a speaking icon). Again - sorry for any difficulties/rather limited scope.