Fun game! The added pressure of finding water helped with with some added danger. Might be nice to add some variety to the zombies, some easy, some harder. Having 3 shots per zombie was nice for planning, but meant I knew I could always handle 2 then had to run.
I also got stuck on the terrain a few times and had to wiggle to free myself, but staying away from door frames helped. The music fit the desert theme well.