@zella: There's apparently some other less obvious stuff as well, for example. During the videotape sequence You can find a lockpick behind the microwave and use it to unlock a drawer also in the kitchen. Then when you get back to the present there is an axe in there you can use as a weapon. No one seems to know what it's for yet though.
Really hoping this game has a PT style tail where it's like hours of people beating their heads on it to figure it out. But it's hard to see where there could be much else.
Also if you get the axe and then go up the stairs, the phone call goes differently than if you didn't have the axe
Has anyone figured out what the dummy finger is for yet?