Is this a UK thing? Because in the U.S. Store you can browse all movies in a particular genre. For example, if you choose “Action and Adventure” and navigate to the middle of the screen, you’ll get some select sub-genres followed by all Action and Adventure titles grouped into A-E, F-J, etc.
It’s fairly easily to understand. If you know what the movie starts with it’s easier to just go to search and type in the first letter of the movie title.