Should Ouka 2 anti-aliasing be turned on?

Don't.

Anti-aliasing is a kind of mosaic, which can reduce the jagged pixel grid on the edge of game graphics and make the picture look finer instead of full screen. The larger the value, the better the picture. Also translated as edge softening, anti-aliasing, resisting image folding damage, etc. Multisampling antialiasing is a special supersampling antialiasing (SSAA). MSAA first came from OpenGL. Specifically, MSAA only performs supersampling and antialiasing on data in Z buffer and template buffer.