First of all, nice game! I like the fact that you have to store the collected nuts in the shed. But then the problems start.
1. The game speed only progresses if the nuts are stored and the score registered. I don't know if this was intentional, but it encourages one to keep collecting without storing.
2. The game speeds up to impossible speeds. The moment I stored like 70 nuts, the game became extremely fast. Unplayably fast. It wasn't fun anymore.
3. When you reset the game, the speed does not reset.