I managed to get in a point where i couldn't find a single penny to craft a shovel to craft a branch to craft the third skull... then i accidentaly closed the tab...
In total, it currently has the right amount of objects to create a single ruby and one skull with the right combination, but it also does feel pretty scarce so I can see how these accidents may happen. It's a tricky balance to not flood the game to make it toooooo easy but I will say there are also branches, matches, and duckies in the map aside from just pennies, shovels, and glass. Thanks for playing!