BUG FIX : TriggerArea display on rocks
PLUS : Speed down/up gameplay

* two buttons on the lower-left corner
* tweaked towers
* started working on sniper/sharpshooter
PLUS : You unlock forests at level 5

* changed with recycling station because options regarding resource gain
increased, but not options regarding handling pollution.
PLUS : New levels

* added new scenes for level 9 and 10