Megadev isometric

Start with the game's coordinate convention, footprints, surface connectivity and camera. Preserve its chosen art, controls, world scale and movement. Lantern Conservatory demonstrates these contracts; its floating garden, lanterns, palette, music and bridge layout are illustrative, not a required look or game structure.

iso_* is application C, not a Megadev isometric engine. Reinspect ewrogers/megadev:latest before using SDK/BIOS interfaces. Do not import SGDK sprite, resource, fixed-point or map helpers. Ordinary isometric drawing uses the base VDP; the Mega CD ASIC may transform selected assets but cannot infer visibility order.

• Coordinates and surfaces: projection, inverse picking, feet, height, stairs, underpasses and camera bounds.
• Ordering and occlusion: projected-volume relations, explicit support constraints, static caching and bounded failure handling.
• Megadev integration and validation: native assets, sprite ordering, Word RAM, DMA, tests and physical-hardware limits.