I will give 2/5-3/5
First, the background is not quite suited the game.. Second, the graphic can be more interesting.. Third, the screen should be bigger..
For the last part, it is misleading people to switch in 9 squares, although people can try to switch in every same figures.. Also if not getting hints from the video, I think no one know about how to switch in the numbers and get the key at the end.. In my opinion, the beginning is quite good, but the last part is not logically of creation.