Ahh yes sorry the key you get is actually the one for the attic (which you can then access the roof through). That's kind of confusing if you don't hover over them for their item names in the inventory. The key to the second house was hit by a last minute bug and it doesn't actually spawn when it should - sorry! The third house is also perma-locked due to another last minute bug... Frustratingly both of these were caused by fixing a different bug... That IS fixed! Don't fix your code last minute kids!
So yes sadly it is missing access to a bunch of content that is in actual fact all in there. But at least you can still kiss anything - that is, anything else!