Here is the full list of all 18 Boxville achievements worth 1,000 gamerscore.
Deliver Grandcan home
Give a broom to Yardkeeper
Fix Pumber's blueprint
Turn on the water for Gardener
Give a worm to Fisher
Win Towers game
Return the thimble to Shoeshiner
Give a clover to Player
Give the fish to Bums
Fix Operator
Fix the elevator mechanism
Return the headphones to Security
Catch Bandana can
Give a toy to Bully
Free Policecans
Return the leg to Plant worker
Free Rusty
Secret achievement