Very nice and as a WIP this has a lot of potential. Keep up the good work.

My fps is at 32 on average with my AMD Athlon 3800, 2.4 Ghz, 1GB RAM. Smooth enough and my machine is about 3 years old.

Also the ground of jungles are made up of dead and decaying leaves so if you change the green land texture to that it would certainly make the jungle more..um...jungle like