Judas Kyss
Greenhorn
Really late response, but I just had this problem on my computer that has a 4096x2160 resolution.
Right click on your StardewValley.exe file wherever you have it on your computer
Click Properties
Go to Compatibility tab
Change high DPI settings
Check box for High DPI scaling override and change scaling performed by to system in dropbox
Start game
Alt+enter if the game starts in a fullscreened, zoomed out mess
Click box in upper right hand corner on title screen to change from Windowed to Windowed Borderless
Alternatively, you can change Windowed to Windowed Borderless in-game under Options->Graphics.
Other fullscreen resolution issues can be fixed or caused by choosing other options in "change scaling performed by:" dropbox in DPI settings so pick whatever works for you.
Right click on your StardewValley.exe file wherever you have it on your computer
Click Properties
Go to Compatibility tab
Change high DPI settings
Check box for High DPI scaling override and change scaling performed by to system in dropbox
Start game
Alt+enter if the game starts in a fullscreened, zoomed out mess
Click box in upper right hand corner on title screen to change from Windowed to Windowed Borderless
Alternatively, you can change Windowed to Windowed Borderless in-game under Options->Graphics.
Other fullscreen resolution issues can be fixed or caused by choosing other options in "change scaling performed by:" dropbox in DPI settings so pick whatever works for you.