The hare continues to lose health. He has to get health points to keep the energy up. There is a countdown timer. The hare can extend the time if he rests. But by doing that he will continue to lose energy. So, he has to be very careful when choosing between health points and running to complete the level and how much time he wants to gain while idling his energy away.
Keep the exe file and the Data folder together. Double click on the exe to play. Enjoy!