A quick spoiler: there´s two gems, one white and the other green, but only one must be used in the tree. If you use the white gem, it will form a pentagram, and the zombie who you cut before will come and kill you. This is the bad end. If you use the greem gem instead, it will form a hexagonal barrier around of the shack. The zombie will try attack you, but will not get enter. Attack him with the knife or the crowbar three times, and he die definitely, letting behind a black cube. This is the good ending.
I think the players are all in agreement with is ridiculous always lose the old car, because we got a new car. And come on... how we can continue spending gasoline,with the engine stopped?
A quick help, for who is seeking the two ends (It will be a spoiler... duh!): the white pommel door is the one who determine the end. Pass for this door, and you get the alternative end. Ignore this door for get the normal end.
What I suggest is a two players mode, exactly for play with the friends. Is a really fun simple minigames colection you have here, I give 5/5 with merit!