The x axis is unlabelled, there's literally no way to know if you're close to the correct probability mass.

It's probably a fascinating game, but I have no idea what I'm doing.

You should add a Wasserstein distance mode.

https://en.wikipedia.org/wiki/Wasserstein_metric

Kuala Lumpur, Malaysia? (fondly known as KL)

This game should just give us a pen tool to draw the line instead of whatever that drawing tool is.