Animate setter and conditional pause

I'm afraid my math is not going to work, so I need help.

The details of the problem are shown in the image below. The block is from the official Animation library.

I think this is what you mean:

The main thing is that the condition you're testing has to be a predicate, not a Boolean, because you're testing it repeatedly. But also, you might as well use WAIT UNTIL to wait until the condition no longer holds.

Yes, that's exactly what I was aiming for, but I couldn't figure it out on my own.

Thank you for pointing out that the condition does not automatically (I know what I am gonna say is terribly unscientific) "refresh" itself; it needs to be called in order to do so.

Your solution was put to work in the project below, a remix of the original one made by fridolinux.

When you stop the project, it says

Error
cannot operate on a deleted sprite

But I like it!

Thanks, warped_wart_wars.

If you liked this one, you may like the Bernat Romagosa's 'Snow' remix, as well.