Unpacking

Green thumb:
This one is pretty easy to do, just unpack stuff and eventually you will find all the plants. Not sure if you have to place to place them on a shelf, but that is what other guides are saying. (At least those I have looked at.)

1 plant in 2013
1 in the computer room

8 plants in 2015
1 in the kitchen
3 in the bedroom
4 in the living room

Gotta flush 'em all!:
So far I have seen you only find the toilets between the years 2004 - 2018, then just click on them and you should hear a flushing sound.

Year 1997 (1st level)

Solve a puzzle:
When you find the Rubik's Cube, click on it with the right mouse button a few times until it is solved.

Blast some tunes:
When you find the Cassette Player. Right click it once to turn it on.

Year 2004 (2nd level)

Strike a pose:
When you find the mannequin. Right click it a few times until it is dabbing.....

Electrical hazard:
When you find a toaster, put it in the bathtub.

A sometimes food:
When you find the Cookie Jar. Place it on the highest shelf in the kitchen.

Year 2007 (3rd level)

Game on:
When you find the blue game console that looks like a GameCube. Place it on the left or right side of the TV cabinet, then click on it with the right mouse button.

Hat on head:
When you find the Cap. Place it on the mannequin head, which is on the top shelf in the dining room.

Year 2010 (4th level)

Tidy whities:
In the bedroom, collect every piece of underwear and socks (that are not in the boxes) and place then in a drawer.

Brew some coffee:
In the kitchen, put all the coffee related items on the table, dont know everything that is needed but some are:

Mug
Coffee brewer
Kettle
Coffee bean bag
Coffee grinder
Water boiler
Milk jug

Year 2012 (5th level)

Rediscover childhood:
Open the drawer under the window, take the poster. Hang it on the wall.

Year 2013 (6th level)

12:00:
When you find the Microwave, click on it with the right mouse button a few times.

Brilliantly solved:
When you find magnets that looks like numbers, place them in this order: "1 + 2 = 3"

Year 2015 (7th level)

Fuzzy friends:
When you find the tiger plushie, then place it next to the pig plushie.

Year 2018 (8th level)

Baby builder:
When you find toy cubes, place them on top of each other to make a tower.