Puzzle/Developmental game_V1

I made a fun modle of developmental game.

Game Instructions:
1.The modle requires two colors of rollball.
2.Assemble it according to the pictures.
3.Shuffling the colors of rollball.
4.Using the sliding block  to arrange the colors of rollball.

Enjoy it.
This model was printed using PLA. (fill in 5%-10%，using a lower layer hight 0.2mm，no support)