Hi,
I'm currently making a 2D pixelart game for PC's (
https://forums.tigsource.com/index.php?topic=68867.0) and uses a full screen, no matter what the resolution the player has chosen. But now I'm implementing dialogue windows, to be used when solving puzzles and I need a certain amount of height in order to have room for all the elements, so I took a glance at Steam's hardware survey
https://store.steampowered.com/hwsurvey/Steam-Hardware-Software-Survey-Welcome-to-Steam and can see that most users use 1920x1080 as primary resolution with 1366x768 coming in as a second.
(I can't make my dialogue windows resize to a smaller size, as I wont have room for all needed elements, so that is not an option) - All other screen elements scale their positions according to the screen size, so no problems there.
So to reach most players, I need the players resolution to be a minimum of
1366x768 (I actually went for 1280x768 to be safe), but what do you aim for?