I'm in China. I can really feel your troubles. That's true.
Schools usually put students of different level into the same class. So when teachers have this mix-leveled class, they often couldn't take care of all the students in the class.
I taught this kind of class many times. Finally, it's so hard to keep an eye on every student. So I focus on the middle levels, try to give more to the higher levels, and seperate a little time to the lower levels. Different level different requirements.
After the class, I would give the lower level a special care.
Don't expect them to improve fast. If only they are improving, that's ok.
For games. I use visual aids, pictures, music, video. Teaching little kids is really exhausting. If I'm not happy, my stuents won't be happy. If I don't dance, they would not move.
Hope this would help a little.