Zanax EX is an enhanced version of the vertically scrolling shooter Zanac A.I.. While preserving the locations and the gameplay system of the original version, this release builds upon the graphical enhancements of the Famicom/NES version of Zanac A.I..

The backgrounds are noticeably more detailed than in the original version, also, some locations have different graphical design. The scrolling is also smoother than in the previous releases, effectively altering the feeling of control and gameplay speed. The status bar, which has occupied the right side of the screen in the original release, has been moved to the top of the screen, occupying significantly less space.