Lvl 20 is hardest in this game . You have to catch 2nd ball in tower , fly to left-bottom corner , let it go and fly above tower. If you will be careful you will not touch any wall. I made it after about 30 - 40 time so be patient.
Lvl 8 is not so hard. Just fly with max speed so it will not increase your altitude so much. Then slow and press down arrow. I had to try about 10 times to do it.
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