Thank you so much for buying!
It has been sometime since I made adjustments due to the newest game project I've been working on. There is only one game mode, I planned a survival type mode. Be reassured the game is a great challenge after many updates and at least 8-9 hours of story!
I should change the difficulty option for a future quality update. :) I'm working on an update that will remove the prompt from the start of the game. Sorry again for that confusion and please leave any feedback for me especially improvements you would like to see in future.