Level completion popup should include "new puzzle" button. (Having to close the popup and then hit "new puzzle" is unintuitive.)
Mobile improvements:
Play area should take up entire width of screen
Buttons should wrap or be made smaller?
Supporting features
Re-organize buttons
"new puzzle," "reset puzzle," "add tube," and "undo" if added should all be together as "game controls." should be closer to the play area than other buttons
"save"/"load" and customization buttons should be in a different place from the game controls. should be further from play area
Improve clarity of button text?
Add icons to buttons?
"new puzzle" sparkles | test tube | shuffle arrows
"reset puzzle" refresh arrow(s), winding left if possible to communicate rewinding
"add tube" plus | plus tube
"undo" undo arrow
"save" floppy disk | download arrow
"load" folder | upload arrow
"customize colors" paint palette | test tube, if unused | water droplet
Main feature(s)
Supporting features