Really fun game! A well-created concept with an enjoyable gameplay loop!
I loved the chaos the game brings when I push all the boxes together---which is a really fun part of physics games. From there, the game became really interesting as I am trying to load boxes in a big pile. Many boxes flies around and hitting each other is a fun challenge in this game.
A part to add could possibly be the forklift lifting speed, giving more risk and more rewards.
Great job!
(I read the comments and found out THE FORKLIFT CAN JUMP Amazing)