Had a go at this one, and I was holding my own until it had slowed down so as to be unplayable when the counter in the upper-right corner read "6." After that point it seemed like the game was chugging along quite slowly. I wasn't able to be killed, so I closed the EXE.
I like the fact the player had a little assistant to help blast the zombies. I couldn't pick up on much else, though. Do you have any more detailed instructions for the game you can share?