RustHeir

Chess where the board crumbles under your feet

Every square you step on wears out. On the third crossing it is gone — and the tile falls when you **leave** it, so you can always stand on spent ground. You just cannot come back to it. And you never keep your own moves. 

You move like the last piece you ate.

Eat a knight and you jump; eat a rook and you slide — and a rook slide melts every square it crosses, not just the one you land on. Those two rules meet in one sentence: **the shape you carry decides how much you destroy.** So the puzzle is never "find the path". It is: find the order of meals that does not destroy your way back.

69 hand-checked puzzles

Every level is verified by a solver before it ships: it is solvable, its par is the true minimum, and it punishes at depth rather than on the first move. A generator built them backwards from an intended solution; a filter threw away everything that forgave you.

Four mechanics arrive one at a time, each with a level that teaches it:

- the anvil — decay becomes reversible, once, in one place

- granite — ground with topography, not uniform rot

- the clock (level 25) — tiles marked with an hourglass rot on their own, one point every three moves, whether you touch them or not

- the road (level 65) — the sign flips: the board starts half gone and every tile you leave *alive* becomes permanent. You build instead of burn.

Also on Commodore 64 and ZX Spectrum

Not ports in name only: the **same rule engine**, the same 69 levels, the same pieces. One C file compiled for the 6502 and the Z80, and a test that replays every level move-for-move against the original to prove they never drifted. 

- C64 — `.d64` and `.prg`, SID music on a raster interrupt, 3×3-character tiles, joystick or keys.

- ZX Spectrum — one `.tap` for both machines: on a 128K the AY plays the same nine tunes, on a 48K you get beeper effects. The tile grid lands exactly on the character grid, so there is no attribute clash anywhere.

(Tested on actual ZX Spectrum & Commodore 64)