Ck1 Sms — Development skill for Claude Code

Commander Keen — Sega Master System port

A from-scratch Sega Master System engine that plays **all 16 levels of the original *Commander Keen: Invasion of the Vorticons, Episode One*** plus its real Mars overworld, built with **devkitSMS / SDCC / SMSlib**.

`keen.sms` is a 224 KB SEGA-mapper ROM. It boots to the title screen, drops you on the original Mars world map, and lets you play every level from the shareware episode, collect the four ship parts, and reach the ending.

The engine grew out of a port of [HTML5-Keen](https://github.com/roganty/HTML5-Keen) (a melonJS demake of the first three levels); Keen's own sprite art and the title screen still come from that project, but the **levels, world map, tiles, enemies and tile behaviours are converted straight from the original `*.CK1` game files** using CloneKeen's file-format source as documentation.

Controls

Input	Action
D-pad	Walk / steer (4-way on the overworld)
Button 1	Jump / enter level
Button 2	Fire the raygun
Down + B1	Mount / dismount the pogo stick
Into a door	Walk into a locked door holding the matching keycard to open it

Bounce on a yorp's head to stun it; shoot enemies to defeat them (gargs and vorticons take several hits; the robotic guards and tanks are bulletproof — dodge them). Grab keycards to open the coloured doors, pick up the four ship parts hidden across the levels, and walk into a level's exit hatch to clear it. Collect **all four ship parts** and finish the level you're in to win.

Building

Requirements: `sdcc` (tested with 4.2), `python3` + Pillow, `make`. The devkitSMS pieces (`SMSlib/`, `crt0_sms.rel`, `ihx2sms`) are vendored.

make assets    # regenerate gen/ from the original CK1 data + Keen art
make           # -> keen.sms

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