Cryptmorrow

Build a complete Commodore 64 game in assembly, one playable step at a time

Under the hill of Morrow lies a crypt of sixteen rooms. Torches burn in halls green with moss, skeletons still guard the corridors, bats wait in the dark, and three seals open the portal of the Moss Gate. Cryptmorrow is an original dungeon explorer for the Commodore 64, and this book shows you how to build it yourself, from the first byte on the screen to the finished game with its title, its music and its endings.

The complete game is yours. The companion repository holds the full source code under the MIT licence: the finished game, all eight steps of the book, 22 ready-made experiments, the automated tests and the tools. The game is also there ready to play, as a PRG file and as a 1541 disk image.

Cryptmorrow is the second volume of the C64 Game Manual Series, where every book is independent and brings a new original game to life. Start the emulator, light the first torch and step under the Moss Gate.

Inside the book

• A multicolour bitmap dungeon drawn from 2×2 metatiles, with flickering torches
• An explorer who walks, stops at walls and swings a sword
• Sixteen rooms in four zones, and a HUD with energy, keys, seals and score
• Keys, locked doors, treasures, potions and three seals that open the way out
• Skeletons that patrol and bats that chase, with blows, damage and GAME OVER
• An original SID soundtrack, eight sound effects, title, victory and defeat screens