Good effort, but needs lots of work...
It's not bad... But :
1-It's awfully bug ridden.
Some of the bugs I noticed...
*Your annoying (to say the least) password doesn't actually work.
*Under some circumstances, you can actually keep searching even after your time has run out (which is incredibly convenient but probably not intended), I suppose it's related to some bad check before subtracting the used hours, causing an unsigned overflow (mind you... I know nothing about flash so I'm just throwing some ideas out there).
*You can continue to upgrade your walls and lose time even after they are maxed out.
*The guy you can add in the car with the "turret" is stuck in a shooting animation... but doesn't seem to be doing any damage.
2-Lacks a lot on the story department.
Are you sure these aliens destroyed human civilization? Because 1 dude with a Tesla gun wiped them out pretty bad. And anyway... no further development in storyline makes for a boring game play.
3-Too easy / not balanced.
All you really need in the game is to search and then leave to search some more. Upgrading your wall is useless. If you do have some spare 2h you could repair the wall if it ever got damaged.
Once you find survivors... that's when it really starts becoming easy. Just give them any weapon you have for starter. The fun thing is... they don't use up your ammo! Once you get the minigun... Just give it to them, kick back, relax, and watch how they do all the job for you. (in reality you'd have to sporadically kill the leak)
By the time your two minigunners become insufficient to deal with the flow. You most likely would have already acquired the most awesome imbalanced weapon there ever was. The Tesla gun! It can deal massive damage to a massive number of enemies in seconds. Most of the time, it just cleans up the screen... And that would only use up one single ammo. At this point... with the two infinite minigunners + the Tesla gun, the game is pretty much the same stuff repeating.
And seriously... what's the point of moving? You don't really need it. And it's not like you can move THAT much anyway. You're stuck in an incredibly tiny area anyway.
The night fight where a good concept... But hardly adds to the difficulty.
There are what? 4 types of enemies? Against what? 8 different weapons? Not exactly the most balanced thing out there.
4-Incredibly repetitive and boring after a short while.
You should have had more types of enemies with different susceptibilities to weapons. Bringing a little strategy to this game where everything could be summed up to, charge Tesla... release Tesla.
Building traps is a good concept... except that at first, it's that much more important to search for ammo and survivors. And later... you basically don't need them anymore.
The time required for each action should be tweaked a bit to balance that up. Or even better... I propose that you should be able to assign survivors to task for each time slot. Making the extra survivors you find actually useful... I finished the game with what? 28 survivors? All of them useless except 2?
5-Bad grammar.
I know, you might not be a native English speaker. I'm not either, and my own grammar is pretty bad, whether in English or in my own native tongue. But bad grammar destroys a story. And a good game needs a story. You should do a little more effort next time.
Bad grammar in a game is like bad acting in a movie... The movie could have the best storyline ever written in the history of human kind, but if the acting is horrible... nobody would like it.