Four letter Word Game

roam

foam

loam

Loaf

loan

lean

mean

meen

meet

feet

beet

beer

bear

boar

soar

sore

Sire

mire

dire

dirt

dart

part

port

sort

soft

sift

lift

lint

pint

pant

part

rapt

Don't think you can do anagrams in this game. So I'll go from part:

wart

want

went

bent

bend

bead

lead

leap