Side project | Slay The Spire Demake

Game Boy Advance | C++ (Butano) [code]

▶ Click to playarrows move · Z is A · X is B
Enter is Start

A deck-building roguelike in the shape of Slay the Spire, re-skinned to Pokémon and built as an actual Game Boy Advance ROM: title screen, region map, turn-based combat, card rewards, shops, rest sites, events, Trainers, Gym Leaders and a card compendium, all at 240×160.

Written in C++ against the Butano engine and built with devkitARM. The constraint is the interesting part — no heap to speak of, a fixed sprite budget, and every card needing its own tile data means the card database, the card-execution switch and the sprite table all get split per starter just to stay inside the limits.

It runs on hardware, in any GBA emulator, and right here in the browser — the teaser above is the live ROM, not a video. Arrow keys move, Z is A, X is B, Enter is Start.

Highlights

• Three starters to pick from — Charmander, Squirtle and Pikachu — each with its own card pool.
• Pikachu keeps the Defect’s orb system: channel, evoke, and passive triggers each turn.
• Items, potions, card upgrades and a save system, all wired into the same turn-flow hooks.
• Procedurally generated region map with combat, Trainer, rest, event, shop, treasure and Gym Leader nodes.
• Scene-graph main loop — each screen is a class that returns the next scene to run.
• Sprites generated from PokeAPI FireRed/LeafGreen art by a set of Python asset scripts.