Title: Hands-On Rust (Chap 8 (Adding a Heads Up Display)
It looks like
.with_simple_console_no_bg(SCREEN_WIDTH*2, SCREEN_HEIGHT*2,
"terminal8x8.png")”
should be:
.with_simple_console_no_bg(SCREEN_WIDTH*4, SCREEN_HEIGHT*4,
"terminal8x8.png")”
I had thought that my HUD seemed a bit bigger than the screen shots, but it really showed up when I added the tooltips and they were way off (being multiplied by 4)
Also… 
another Mac/Big Sur terminal rendering artifact:
It looks like the top row (or 2??) of pixels are being occluded.