I got to level 3 before accidentally killing off all plants and having to quit. As Ben.Toasty said on the other page, a way to reset the level or simply enforcing that a single shrub always survives would be nice, especially seeing how the game is so rooted in trial-and-error. It might be obvious, but I found that every level should be started with maximum resources to fill it with plants initially, before adjusting them down. Lastly, as a nitpick, I find that maintaining plant sizes is not so much evolution as gardening, but that may be just me. :D