After we have pass 20 level on this game now we arrive at level 21, you have to be careful on level 23 because you must pay attention to the direction of rotation of each gear. This my 100 Doors Runaway level 21 to level 25 walkthrough to help, check this out
100 Doors Runaway Level 21
At this level you must figure which one the weighest on each chain then pull it down.
So you must pull down TV, weight and stove.
100 Doors Runaway Level 22
Drag the box to the center then tap the faucet until the box touch the red button.
100 Doors Runaway Level 23
Take 8 gear on the floor then put it on the wall. But you must put the gear on the right position to make right rotation.
100 Doors Runaway Level 24
Tilt left your device until the ball slide down then take it and use it to bird picture.
Now take broken glass on the floor to get 3 shape then put it on the door on the right place.
100 Doors Runaway Level 25
See the arrow on the door, you must slide the door follow the arrows that appear.
So you must slide right-left-down-up.