All the answers here! The main goal in 100 Doors is to escape the room. Using all the possibilities of the device you need to open each of 100 doors and move the doors to the next Level.
Search for hidden objects, solve puzzles and use an items to do this!
Grab the broken key on the floor
Tap the portrait to make the tool fall
Use the tool to open the closet
Grab the tape and use it to repair the key