For educational games, it is very important that the graphics are attractive and fun in order to get kids full attention.
Backgrounds:
Characters:
I am not much of a fan of this 2D art, they obviously try to emulate a Popsicle show, but it seems a bit limited to me.
Messages:
Perhaps one of the best visuals the game has is the "Sweet Message" this message appears when the player gets many points in one move. this immediate feedback is great to motivate the user to continue playing as they are doing a good job.
This visual comes next to a sound effect that also congratulates the player.
This visual appears when you finish a level. Some times the user takes days or weeks to finish a level, it is important to give them a great positive message congratulating them and leading them to the next level.
Level:
The items in the level have a great shinny look. notice the highlights in the green and blue candies. also notice how the hud is very simple, most of the visuals is the game board.
The combination of colors also works really well.
My Thoughts:
-Have shinny and Bubbly elements.
-Congratulate the user after a big effort.
-Have constant positive messages for minor achievements.
-Sound effects really help you motivate the player.