Play Bio Senshi Dan: Increaser Tono Tatakai (Japan) - Sci-Fi Action Online Free

Bio Senshi Dan (Bio Warrior Dan) is a 1987 action-adventure by Atlus/Jaleco that blends side-scrolling combat with non-linear exploration. In a post-apocalyptic 2081, Dan travels back to 1999 to stop the 'Increasers'—alien entities that grow stronger over time. The game features a unique timer system: if you take too long, the boss becomes much harder to defeat. With its dark sci-fi atmosphere, upgradable weapons, and emphasis on speed, Bio Senshi Dan is a hidden gem for fans of games like Metroid and Blaster Master.