itch.io

Sadly my screen died while testing, I can't tell you right now if the square flickers.

I have indeed a Super CD-ROM² compatible system (that I have to repair too), but no Arcade Card

Edit : tried on a regular OG White PC Engine with an HDMI adapter, the red square does flicker a bit at the top when the screen scrolls while I follow it. It doesn't when my character is static.

Grass or water effect is perfect

Very impressive proof of concept. Tried it on a PC Engine GT, works very well, but the wheel text isn't legible (though you can go by with the icons).

There's a red translucent square going left to right at the top of the first field screen.