First select easy.
When the game starts it is Monday. This is when you have the most customers.
Just go slowly aiming for the door and avoiding obstacles. You need to hit all of the bright colured "welcome" mat houses, not the dark "go away" mat houses. The mat will change if you hit it right. Alternatively you can hit the mail box with "sun" on it. This gives you a bonus, and can sometimes be easier.
If you are solely going for this achievement, if you miss one, press start, and quit, and start again.
Just keep going slowly, I believe you can die as long as you don't miss any. Good Luck