You hit the nail on the head!
Fun fact, I joined this game jam 3 weeks late so I only had 1 week to do this, hence the lack of sound, UI styling, feedback and content for emails and upgrades. There's still a lot I want to add so I may continue working on this in the future! I did have plans for upgrades to increase email spawn rates, rare emails that are harder but reward more, auto-solving emails (not always 100% correct), etc.
Thanks for the detailed feedback, and for playing!!