For those determined to proceed, here are less-risky avenues:
Avoid at all costs:
Check forums like:
Would you like a step-by-step guide on using Cheat Engine to make your own infinite ammo cheat for Chicken Invaders 4 instead? That would be completely safe and educational. chicken invaders 4 trainer 8 repack
Go to Options → Difficulty and select Easy. The chickens shoot slower, drop more drumsticks, and bosses have less health. This is effectively a built-in trainer. For those determined to proceed, here are less-risky
Because Chicken Invaders 4 has a brutal difficulty spike by the third planet. Without cheats, you must memorize attack patterns, farm for drumsticks (health), and avoid losing upgraded weapons when you die. A trainer removes this grind. Avoid at all costs: