There are various types of keycaps. They can all be one size, they can be different heights on each row, they can have letters printed on ($) or they can be several layers of different colored plastic with the letters being part of the molding process ($$$).
I downloaded this one to watch on a long plane ride recently and I guess I forgot what all was involved with it. It did not play for more than the intro credits before I was fumbling to close the app.
Good luck! Happy to answer any other questions that might come up.