No need for apologise, it's just a gamejam!
If dissapearing locusts was a layering issue they would've returned when away from crops, they didn't.
About suggestions: I think exaggerating can help make the game more interesting. Increasing eating speed and amount of locusts spawning after fully eaten crop will fix slow start, and making bigger crops with large groups of chickens further on map will force player to avoid them until swarm is big enough to eat everything and run away. This is the way I see it.