what I do:
put the paper in the fireplace
Put the wood in the fireplace
light the fireplace
put all but one of the rockets into the fire one by one.
open the two presents.
Put the disc in the player
Put the body of the robot on the stand.
Put the head on the body
Put the battery in the body
Put the arms on the body
Arm the robot with the darts on the shelf.
Put the cat (On the left border, Katze, in German) in the bag.
Click the plant on the shelf to get a stone, but this in the cookies.
Use the gasoline on the upper left corner of the TV
Put the remaining rocket in the vase.
Wait until santa walks over to the left.
Open the chest drawer.
Put the mouse traps on the floor.
wait until he gets his face mauled by the cat.
afterwards, put the skateboard just to the right of him.
Open his parcel and balance the bowling ball on the curtains. After he crashes, light the rocket in the vase.

I know there's something I'm not doing with the hamster but I cannot figure out what :(

when santa points at the sky, put the hamster in his coat. there ya go.

What about the darts sitting next to the stereo? Must be something you can do with them, but I can't figure it out.