Optimized graphics by size using 'optipng -o5 -np -nc -nb *.png'

compensate a bit for the reduction in power by increasing target height, avoids bouncing off terrain.

Revert yet again for breaking stuff. No more chances on this. If there'd been a release, this would have been twice with serious breakage. P.S. - as per koda's complaint last time, only reverted the non-iphone, probably means iphone is now broken. Oh well.