Bio Senshi Dan: Increaser to no Tatakai, developed by Atlus and published by Jaleco in 1987, is a sophisticated blend of side-scrolling action and non-linear exploration that arrived years before the "Metroidvania" genre was fully defined. Set in a future where Earth is besieged by mutating alien lifeforms known as "Increasers," players control Dan, a cybernetically enhanced warrior tasked with infiltrating five labyrinthine stages to eliminate the core threats. The game features a unique sense of urgency driven by a ticking clock; the longer you take to navigate the environments, the more the Increasers evolve and grow in strength, making the eventual boss encounters significantly more difficult if you linger too long.
The gameplay loop is surprisingly deep for an 8-bit title, requiring players to manage a currency called "Zenz" to purchase essential health refills, weapon upgrades, and defensive items from shops scattered throughout the levels. Combat is tight but requires precision, as Dan’s primary attack has a limited range until specific power-ups are acquired. Navigating the world involves a mix of platforming and backtracking that feels reminiscent of *Metroid*, though the specific focus on boss-centric timers adds a layer of strategic tension missing from its contemporaries. The fan translation is essential for Western players to fully grasp the shop menus and the lore-heavy dialogue that bridges the gap between missions.
Visually, the game showcases Jaleco’s distinctive late-80s aesthetic, featuring detailed sprite work for the grotesque alien bosses and varied environmental palettes. The soundtrack is a standout feature, composed by Tsukasa Masuko, offering a driving, heroic score that complements the frantic pace of the action. While the difficulty curve can be punishing due to the time-sensitive evolution mechanic, the rewarding progression system and responsive controls make it a premier choice for NES enthusiasts looking for high-quality imports. It remains a fascinating look at the early design philosophy of Atlus before they transitioned into the RPG powerhouse they are known as today.
