Got the plants working in a "creep" like fashion now. They cover a radius around where you planted and slowly draw in instead of just having a static plant that vanished after a time. It sounds like a minor difference but the visual impact of seeing the foliage withering away was really satisfying.
Next up is working on Enemies. I found a free scorpion model on Turbo Squid and am going forward with that, any of you know of other places one can find free fauna models?
I was really worried that this project was falling apart before this week but several things have come clicking together.