fixed tutorial not showing up
fixed difficulty starting at 1
started the UI at 170%
added a little colour to the grass
flamethrower
lvl 1: 0.8 dur -> 0.4 dur
lvl 2: 1.2 dur -> 0.5 dur
lvl 3: 1.8 dur -> 0.6 dur
nailgun
lvl 1: 300% mult -> 100% mult
lvl 2: 600% mult -> 150% mult
lvl 3: 700% mult -> 250% mult