Cool game! It was fun wondering and exploring the world. Level design was good, but I think you should shorten the grass or give player a sword or scythe or lawn mower xD or something to cut the grass. It became a bit annoying that you had to jump all the time to scout the area. Also make a sound when player picks a red ball and add a counter how much player needs to collect them to proceed.
At the very beginning you could tell player what to do. Maybe it would be enough to put the first collectable right in front of player and after it is collected tell the player that goal is to collect them all.
Houses could not be entered. Add a door if that was made on purpose.
Graphics were nice and the mood of the game felt relaxing. :) Keep it up!