All righty, let's take a shot
From left, to right:
Turd NO, shark NO, robot NO, red howler YES, big red monster NO, alien trooper YES, alien trooper YES, red guy NO, green guy NO, green gut with flash NO, green guy with human arms NO, skinny green guy NO, purple guy NO, worm monster YES, head with hands NO (it's from AB3DII TKG), head with eyes YES, eyebal for a head guy NO, red wingy alien (final boss) YES, alien trooper YES, gigeresque alien NO, alien trooper YES.
But... you have four alien troopers. As I recall there were only three of them. Pulse rifle trooper, shotgun trooper and plasma gun trooper.
Someone correct me if I'm wrong somewhere. Let us help our friend
