This is a pretty nice skin, js.
I suggest making the combo colors lighter (maybe pastel colors) to fit the theme of the skin. Maybe making the score numbers the same font as the ones for the default numbers would be a bit cuter (maybe for hit0.png, hit50.png, and hit100.png/hit100k.png too).
There are a few things that are a bit low in quality:
-Mod icons
-The little character on scorebar-bg.png
-menu-back.png
-inputoverlay-background.png
The alternative menu-button-background.png needs to be fixed since there are pixels sticking out on the top corners. Also the skin.ini is a bit messed up- at least for me.

Might want to fix it as well if someone else has the same problem.