Hotfix #5.1

FIXED game crashing when scrapping RAIL GUN at the edge of a tile

GENERICO PRIME now has considerably lower ENEMY SCALING between wave 30 -50

ADDED two new HINTS for new players

REMIXED SOUNDS, so that all sounds have comparable volume

BETTER SOUND MANAGEMENT overall, so that the game does not run out of available sound channels

ADDED ENEMY DYING SOUND, for a satisfying feeling after putting one of the poor buggers down