It’s not the first question about this subject, but I have tried the suggestions on the forum but they don’t seem to work.
I have build my retropie in a original game boy case, using a 3.5 inch tft screen. All worked out nice and I have croped the screen so it fits exactly in the original 160×144 screenwindow of the game boy. I also changed the resolution in config.txt to 160×144. This all works.
EmulationStation also crops nice in to the 160×140 screenwindow but I can’t get the resolution to change. I think a lower resolution would be better, because the text in EmulationStation is not readable.