100 Floors: Level 28 is a fairly difficult stage if you don’t know the solution and is trying to guess. On this stage, when you tap the screen the gray area lights up with a rainbow color that lights up the door. Players might think what does this mean but the solution to the riddle is right above the door. There are dots about the door. About 8 in total and each dot is placed in a certain order where they are closer together or separated by a distance.
To beat 100 Floors: Level 28 you need to tap the gray area of the door to light up the gray area. Follow the dots and tap it in that order. If there are two dots together you need to tap the gray area two times before the rainbow light goes away. In this stage you should only see the rainbow area light up a total of 4 times because the first two dots are together and so forth.
Once you have completed tapping the rainbow and gray areas you will advance to 100 Floors: Level 29.