There are three endings to this game~
To achieve ending 1 (the good ending), you will need the following in-game items: cat treats, key, house key, pen, paper, photo, and perfume.
To achieve ending 2 (bad ending), you will need the following in-game items: cat treats, key, house key, photo, and perfume.
To achieve ending 3 (bad ending), you will need the following in-game items: cat treats, key, house key.

-- You can obtain the cat-treats from the wastebasket in the kitchen

-- You can obtain the key (key to the living room) from the second of the two cats in the lower left corner by giving it the cat treats

-- You can obtain the house key (key to the front door) from the table in the living room

-- You can obtain the pen and paper from the purse in the bedroom by the front door

-- You can obtain the photo from the box in the basement

-- You can obtain the perfume from the bedside table

There are also some certain dialogues that will only occur if you have a certain object in your inventory. For example, if you're holding the birthday card, one of the cats will take it from you and use it as a litter box. Another example would be the homeless man- if you do not have the mug and/or the donut, the homeless man will call you "a capitalist bastard", but if you do, he will take the food and thank you instead.

Another hint: The road doesn't lead anywhere, Emma's house is on the right and you can enter it by walking into the bricks.