more props than most...
You deserve more props than most reviewers are giving you. I actually enjoyed the concept that I could NOT kill the enemies. I would suggest adding a really tight and well designed tutorial, though. I had some problems understanding the rock walls at the beginning, and even more problems trying to apply the knowledge that grenades stick to fungus walls. If you continued the small tutorial "section" at the beginning, so that players would understand more of the strategies, this could be awesome. At the point where killing enemies becomes possible, you could then extend the game and add more weapons etc. By that time, it would be reaaallly satisfying to crush some of the enemies that have such a huge advantage during the early parts of the game.