maybe in the third one, one of the food sources could be domesticating wild birds

engioneering could be required to build a pen, a higher science level could be needed as well

then the children could have to capture a certain number of birds to comlpete the puzzle

villagers could collect eggs for food

ocassionally the pen structure could deteriorate and the birds will escape and have to be recaptured if it is not repaired

the fire is on a count down timer, maybe this could have a similar mechanism, except that instead of completely refilling the timer bar it could be a percentage gague that goes up 1/2 a percent every time they work on it, and a whole percent everytime they got get rocks or wood to use to fix it

the farmers could collect eggs, and also have to feed the birds small quantities of theier own food supply, both adding to skill levels

if they are not fed, the deterioration rate of the pen could multiply 10x so that they escape