Thanks so much for checking out our game! And you are absolutely right: Getting the right balance in this game was hard. We've had a few friends play the game and struggle - others said it was too easy.
The UI is something we didn't really put a lot of time and effort into: Since it's our very first game, we tried our best to implement the main mechanics. But we are already adding the UI to our roadmap for our update! :) Thanks so much for your feedback.