I get this issue as well.
I don't know for sure, but I believe it has something to do with the engine and how it goes about scaling.
Have you tried messing with the screen ratio in the settings [ the width and height values ]? I think fiddling with these values may help a bit.
Again, though, I'm not really sure how to fix this. Would love one of the devs to go in depth about how Superpowers does its scaling.