There is mini game featured on BBC language center. Two games are included: tones and characters. Both are very important for students to master.
The tones game has two parts: “Learn the Tones” and “Straight to Play”. In the “Learn the Tones” section, one can learn to pronounce symbols in 5 tones (4 basic tones plus neutral) following instruction. In the “Game” section, one can practice to see how well s/he has mastered the tones. I think it is a quite good game for kids to go over all the basic tones in an effective way.
The characters game has also two parts: “Learn to Write” and “Writing Game”. 60 characters in three levels are listed in the “Learn to Write” section. One can watch the order of strokes for each of them and try to write after watching. In the “game” section, one writes according to the pronunciation. It is a quite good game to master the basic 60 characters.