Thanks for the feedback! What was wrong with the screen ratio?
It was zoomed in further than it should have been, and so it was hard to see some things near the edge of the screen.
Ah yes, I'm familiar with this bug :( It plagued every hour of my development.
Apparently, it's a bug with the version of Unity I used. I found a workaround which was to switch the game to windowed mode and then back to full-screen mode to fix it!
