Wonky Space Invaders in MAME on Nvidia Shield

Please help me set up MAME on the Nvidia Shield properly. My Space Invaders looks like it is melting.

I have tried all the MAME and Final Burn Alpha cores, tried various combinations of Fullscreen settings and resolutions and tried a dozen Shaders.

Is it possible to make MAME look ok on the Nvidia Shield or is it an impossible dream?