I'll second the other comments that the gameplay is a bit simplistic.   Good use of this graphics pack otherwise and I loved the choice of music!  
Minor graphical glitch to report, sprite for 'shot' enemy appears offset sometimes.  Here's a screengrab of what I mean.

I think the other comments highlight what I was going to say. I didn't find any real gameplay loop, point or challenge in this, though what IS there (shooting, running enemies, and level progression) all seem to work without a hitch. At any rate, good job!

Love the art style and music! Really happy to see this project come together as a very complete game! Love that there is multiple levels with different backgrounds. Gives the game a very nice progression feel.

Some notes:

Pros:

• Art + music is great, really creates a nice vibe
• The game ran smoothly for me with no bugs

Cons:

• I didn't really understand the point of the "HitPoints" was my girlfriend losing health? I also didn't really see how I was losing the game potentially
• Wish I could have seen my score on the end screen. Not sure what I got
• Minor comment but would have loved a bullet sound with every gun shot
• I just had my mouse at the bottom of the screen and pressed whenever an enemy passed by. There was no real challenge as the enemies would walk through my girlfriend regardless where she was and I wouldn't have to protect her at all. Thought they were trying to catch her? If on collision they stole her or I lost hit points it would have been a lot more of a challenge

Overall I love the game and it worked really smoothly on my windows machine. A short and sweet experience. The game also feels very complete. Couple of minor gameplay issues and I think this game could be taken to the next level!

It is a good game, however it may be too easy.  Just give the hostage some movement, for example maybe "The Reds" can push her around ,  that way the player cant just hover the mouse in one spot. I also noticed you can click and hold. I do like the music and art choices. they go together quite nicely.