How would I create a traceable shape button and/or create a button that ignores transparency of an image for a minigame?

[im2cool4uboss]

Trying to create a minigame with a traceable series of preset shapes, think like pokemon ranger guardian signs, but cant find out how to force a pseudo button from an image or a way to only click on pixels that aren’t transparent. Help would be appreciated

Working in 5.6