Alien Syndrome, released in 1991 for the Sega Master System, is a side-scrolling shooter with action elements. Players navigate a spaceship battling alien creatures. Unlike its Western counterpart, the Japanese version may feature some unique elements or differences in gameplay or visuals, reflecting localization choices. The game was developed and published by Sega, showcasing the publisher's range of genres within their console library. 

Alien Syndrome (Japan)

Alf (USA)