It might have been just my computer, but sometimes the framerate would drop and then flies would shoot off and exit or get their wings stuck in objects or be left behind by the group. The game should account for that.
Here are some tips if you're determined to reach the ending: characters can die of cold, wild animals, insanity, or you can kill them, but they can't die of hunger. Keeping their mental state up is more important than keeping the food stock up, and even if you're at 0 food, group therapy may be the better option. In fact, view hunting as something to do when you can't do group therapy. Wild animals attack twice and it takes 5 to 7 bullets to fight them off or else you die. Use the dog unless you're desperate, and make sure you always have enough bullets in reserve to survive the attacks. Start by repairing as much as you can, and keep one or two medicine in reserve in case the doctor gets sick. You lose an action for everyone sick or dead, so cure characters as soon as possible-- the action is worth more than the food savings. Once the radio is repaired, you can get into a pattern of days where you do group therapy and days where you cure/hunt/gather wood.
Hint for getting the flower: if nothing in your inventory is heavy enough to open the window, you had something heavy enough at the beginning, so try to get it back. Later, the bird comes to music.
I can't think of any reason why a game like this should run so poorly. Sometimes it's not the computer's fault. Sometimes it's inefficient programming.
I was disappointed when I retired at the end and the unit I selected (a light infantry that I had from the start) was reset to level 1. Still, great game.
I don't like this game as much as your others because it seems like the same strategy with minor variations can be used for each level. But the game is still something to be proud of.