ULNOPSF
Make words with F
Never: plural or third-person -S
FLOP FLOSS FLUFF FOOL FOUL FOULUP FULL FUSS LOOPFUL LUFF POOF PUFF SLUFF SNUFF SOULFUL SPOOF SPOONFUL SPOONSFUL UNFOUL
Pangrams: SPOONFUL SPOONSFUL
score: 90