Nice polish, too easy and short.
The game needs to start a little easier (personal preference), and end alot harder. Make ther a bigger difficulty difference between levels (days).
The population cap was to low, and the repair bonus per pop was too high. Make it like 2% bonus repairing per survivor, you never have to spend more than one hour a day repairing if you do it right.
There needs to be more days than 20, maybe 50, then make more weapons. And it might just be me, but the uzi was better then the next two weapons you got after it.
Something else to spend hours one would be nice too, maybe defensive upgrades to your base (higher resistance to attack, barb wire, spike traps, some oil/glue puddle crap that slows them down, trip wires, ect ect)
On the good side, the presentation was extremely nice, the graphics were superb, and the gameplay was fun enouhg for me to finish the game, albeit short.
Good job, but with some expansion and tweaks this could be a great game.
-Puffs