Mina the Hollower

What It Covers

David D'Angelo, lead programmer at Yacht Club Games, covers the custom C++ "Propeller" engine built for Mina the Hollower, a Game Boy Color-inspired top-down action RPG. Topics include rendering architecture, self-imposed art constraints, Castlevania-influenced combat design, open-world saving systems, and a seven-tier New Game Plus structure.

Key Questions Answered

• •Custom Engine Architecture: The Propeller engine separates concerns into three layers: a core rendering/input/audio system, a suite of art pipeline tools for palettes and animations, and a gameplay engine handling collision and combat systems. Console-specific rendering branches call platform APIs so gameplay code stays platform-agnostic, enabling multi-platform shipping without rewriting core logic.
• •Authentic Art Constraints Without Hardware Limits: Mina draws textured triangles via modern rendering APIs but mimics Game Boy Color restrictions by limiting each sprite to three colors, using a hand-curated global palette, and splitting large sprites into sub-components matching how Mega Man's two-tile character was split across two hardware sprites on original NES hardware.
• •Positional Combat Over Dodge-Roll Design: Rather than the standard attack-attack-dodge loop found in Souls, Hades, and Zelda, Mina's combat uses a 30-frame jump with no mid-air repositioning, forcing players to pre-plan positioning. The burrow acts as a duck, not a universal dodge, with ground attacks introduced progressively to invalidate the burrow as a default escape.
• •Trinket Balancing Across 60 Items: With 60 trinkets and six equip slots, balance required thousands of playthroughs to ensure players who struggle with specific mechanics find relevant trinkets organically. Items target distinct skill gaps: pit avoidance, close-range combat, healing timing, and movement speed, preventing the open-world structure from becoming either trivially easy or inaccessibly hard.
• •Seven-Round New Game Plus Escalation: Each of seven New Game Plus rounds alters the game structurally rather than just scaling difficulty. Round two flips the world horizontally and removes all items. Round three activates a built-in item randomizer that reshuffles all pickups from the opening gift onward. Round seven scales enemy difficulty to endgame levels in early areas, rewarding deep mechanical mastery.