Right now, hunters can shoot acorns indiscriminately.
Therefore, I have changed the Acorn Cannon algorithm slightly:

It now requires the Hunter to be level 5 to shoot acorns.
When hunters try to shoot an acorn, there is a small chance that they might misfire and be blown up instead of their target.
If a hunter is blown up by their own acorn cannon, then they will go back to level 1 instead of their target.
No donguri or seeds are rewarded if there is a misfire.

This is the algorithm that determines the percentage chance of misfire:
- L1 is the level of the Acorn Cannon shooter.
- L2 is the level of the Acorn Cannon target.

The hit probability, P_hit, from shooter to target can be computed by the formula:
P_hit = 0.98 / (1 + exp(-0.1 * (L1 - L2))) + 0.01

If it does not hit, then it will be a misfire.