holding koalas on the screen is not really easy, first you have to learn to control the koalas with little slaps. if you slap in a really really short range the koala will move very slowly. and if you slap directly the koala (not by drawing a line) koala will stop falling down. then you have to stop as many as you can and start the little slaps on lower ones. then they will move to the koala group slowly and by this way you can have combo frenzy :D