You are a hungry mouse in need of food.
The goal is to give your mouse the best life possible. In order to do this, it will have to go and get enough food to cash in and refill energy. First, it will need to dig enough to reach its food. Depending on what it finds the bank will award him with more money.
Use the money wisely; if it is lacking energy, your best option is to go get some sleep at the hotel. If you have enough money left you can go to the store where you will have options to carry more, last longer between periods of sleep, or buy tools to dig better!