Fun but could be much better.
It's a nice game. But I felt character development was slow and linear.
Weapons drop at fixed points in the game, rather than working from percentages. Usually this is okay, but when the levels are very long this system is unrewarding and tarnishes replay value. It took me about 20 minutes until I received my first gun upgrade, and I knew that if I restarted the game it would take the same amount of time. I would have preferred it if for every time I had conducted a search, there was a chance to obtain new weapons.
Enemies don't develop very well either. I can see variations in that some enemies move faster but take less hits to kill, whilst other enemies move slow but take a lot of effort to kill. I believe this made for an unchallenging game.
For me, my incentive for each round was to accumulate the required hours to search the base - hoping each time for something to make my character stronger. Unfortunately once I realised that weapon upgrades dropped at fixed intervals, the appeal of the search was gone.
I like what you've done, and hopefully you will take these points into consideration when or if you produce a sequal.