Overscan is a tricky beast! My usual emulator doesn’t display the top or bottom 8 lines at all by default, so it wasn’t until late in development that I realized some people might be seeingmore of the screen than I was! Ended up modifying my level reader so that it would basically duplicate a row of tiles into the underscan. I’m sure bringing my active area inward by a tile in all directions would make it for sure visible on even the bezeliest of screens though