Yep. The progression is slow and for some people it's boring. This is my first jam and I overreacted the gameplay, so the beginning is very boring because you gain a little amount of money.
I'm glad you like it! In the beginning if you complete a day you get around 100 money. If you progress you get stronger enemies. And stronger enemies give you more money. There is also 2 skills what can increase your income.
I want to add more enemies in the next one week to make the game more exciting. Every enemy is going to have a custom health, attack mechanic, speed and money drop. But I'm glad you like the core gameplay