This game has a great look. I like the design of the cassette and even more so of the the cassette player.
The gameplay was difficult and could use some improvements. Good effort overall though.
I think it would be nice if there was some sort of visual effect when you get a pen so that the player can see what it changes more clearly. Understandably, in a one week jam it is difficult to get all that the ideas in.
Nice work.