Gameboy Zero with Retropie and Super Mario Land?

[WillowNest]

Hi there,

i have build my own Zero Boy and it works I Have an HDMI Display and everything works. But in "Super Mario Land" for Gameboy, the Video is not perfect. I hope i can explain it correct, because my english is not the best. If i run with Mario, the background is not as fast as it should. There ist an effect like "waves". I test every setting on Retroarch, but with no effect. Hrz of the Display i 59 Hz

Anybody any idea?