@mitu Hey mitu! Thanks for the suggestions. I figured it out after - I simply tried plugging it into a TV instead of my monitor, and no issues - I can see everything just fine. I think I had the wrong resolution settings perhaps, or maybe it was something to do with the high refresh rate. Regardless, thanks!
Please do not post a support request without first reading and following the advice in https://retropie.org.uk/forum/topic/3/read-this-first