Just get aa and have a try. It is a little different with UU.
1.Dots on the top of the screen and you just tap the screen is OK. The dots with numbers in aa are at bottom of screen.
2.The UU disk is small than aa, increase the entry difficulty!
3. The disk move direction changes every level. But UU haven't change by level eight.
Maybe there are more different between them since my stage is eight at moment.
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