Solutions :

3-letter words (1 point): 37

ELF; ELK; ELS; EMS; EMU; ERF; ERG; ERK; ERS; FEM; FER; GEL; GNU; GUE; GUL; GUM; GUN; KEG; KEP; LEG; LEK; LEP; LES; LEU; LUG; LUM; MEL; MUG; MUN; PEG; PES; REF; REM; SEG; SEL; UGS; ULE.

4-letter words (1 point): 41

ELKS; ELSE; ERGS; ERKS; EUGE; FEMS; FERM; GELS; GEUM; GLUE; GLUM; GULE; GULS; GUMS; KEGS; KEPS; LEGS; LEKS; LEPS; LUGE; LUGS; LUMS; LUNG; MELS; MERK; MERL; MUGS; MULE; MUNG; PEGS; PELE; REMS; SELE; SKEG; SKEP; SLUE; SLUG; SLUM; SMUG; SPEK; ULES.

5-letter words (2 points): 20

EMULE; FERMS; GEUMS; GLUME; GLUMS; GULES; LEGES; LUGES; LUNGE; LUNGS; MERGE; MERKS; MERLS; MERSE; MULES; MULSE; MUNGS; SEGUE; SLUNG; SMERK.

6-letter words (3 points): 7

EMULES; EMULGE; EMUNGE; LEGUME; LUNGES; MERGES; SKELUM.

7-letter words (7 points): 2

EMULGES; EMUNGES.