Post gamejam update

Found some time to fix some bugs and implement some sugestions:

changes:

• final screen now stays focused on player and snowperson
• snow trails are smoother and blend better
• snowball grow rate is now dependant on amount of snow on the ground
• grow rate is visible as size of the text over snowball.

fixes:

• restarting clears scene properly
• "too heavy" marker shows when trying to pickup ball over 1m
• lowered resolution of ground render textures - should improve performance
• lowered rate of tesselation - should improve performance