Most enemies can be destroyed with Gromit's hand to hand combat
moves. Use them instead of your weapons. You might need to stockpile
ammunition for other tasks.
After you rescue the baby, go to the area where the elephant has
knocked down the doors. To the left of the doors leading to the next
part of the jungle is a water chute. Jump into that water chute and
go into the hole. You will reach a bonus level.