The current themes are: Star Wars and Pokémon. Just answer the questions and have fun. I used my customisability from the last version to do themed questions. I could also apply the same technique to make difficulty options. I have not forgotten about my account choosing though, and will probably implement that somehow soon.
I am going to make a full game out of this on my main account, but keep testing here until I find the most optimal way to do it, so keep an eye out on both accounts for more!