Summary

This is a replacement START button for an 8BitDo M30 controller. This lets you print a start button in the European Mega Drive red or gray, or the American Genesis white, rather than the Japanese Mega Drive blue.

No, it's not going to save the world. But, you know, maybe it will make your controller look more authentic to how you remember it. We should take all the happiness we can find right now.

Feel free to remix, or include in collections, or whatever. If you want to edit it directly, it's up on TinkerCad, just unmerge the object... I needed to shave 0.2mm off the measured dimensions to get it to print correctly, but your printer might be better or worse.
https://www.tinkercad.com/things/4K5LAe2s5GN-8bitdo-m30-replacement-start-button

Print it at fine with 15% infill, no need for supports or rafts.