Alas, I have very little experience with 1 page RPGs.
I’d recommend finding a bunch and looking at them to see what you can learn. From what I HAVE read, they tend to be very focused on one particular thing.
Crash Pandas is focused specifically around playing as a gang of raccoons driving cars
Lasers and Feelings is specifically trying to emulate classic star trek.
The mechanics need to be ultra simple, ultra focused, and very cleanly conveyed so they fit neatly onto one page.