If your screen dims when playing games whether in Full Screen or not in Windows 11/10, then follow this post to troubleshoot this issue.

The windowed mode of Sonic Mania is far too tiny! Here's how to temporarily or permanently play the game in full screen mode!

However, you can enter full screen mode, and get a bit more display space on that external display. And in this tutorial, we’re going to show you how exactly you can do that.

Full screen Selecting Full screen will magnify the entire screen, with the cursor used as the focal point for magnification. Full screen zoom uses the entire display.