Just One Boss Game

Just One Boss is a challenging, retro-styled arcade boss fight game created with the PICO-8 engine. In this intense agility test, you control a small, bouncy blue slime trapped in a grid-like arena. True to its title, the game skips the standard level progression and throws you directly into a single, multi-phased battle against a formidable opponent.

To defeat the boss, you must navigate the grid to collect glowing white tiles that appear randomly across the screen. Each collected tile inflicts damage on the boss, but collecting them becomes increasingly difficult as the enemy unleashes a barrage of unique attacks. From expanding hazard zones and flying projectiles to splitting your character into two separate entities, you must maintain sharp reflexes to survive the onslaught.

Controls

You can control the game using either a keyboard or a gamepad:

• Arrow Keys / WASD: Move the slime around the grid.
• X Key / C Key: Perform menu selections and start the battle.

Gameplay Phases

The boss battle progresses through distinct phases, each introducing new hazards:

• Phase 1: The boss shoots standard projectiles and creates basic blockages.
• Phase 2: Spawning flowers and playing cards are added to restrict your movement.
• Phase 3: The ultimate challenge where your slime is split into two, requiring you to navigate both characters simultaneously.

Tips for Survival

• Prioritize Dodging over Tiles: Tiles do not disappear immediately. It is always safer to wait out an attack cycle before moving in to collect a tile.
• Learn the Mirror Mechanics: During the split phase, your movement inputs affect both characters. Focus your eyes on the character in the most danger to guide them to safety first.
• Look for Safe Zones: The boss's patterns are mathematically designed to always leave at least one safe spot on the grid. Find these zones to catch your breath.