With virtually all of my spare time over the course of 1.5 years, I developed a video game based on the original Super Mario World by Nintendo. Using an editor called Lunar Magic, I built a full gaming experience from from scratch. This includes level design, aesthetic design, overworld design, and lots and lots of custom assembly code.

I had never done any level design before starting this game. My first 10 or so levels were painstaking and came out rough. Shoutout to my playtesters for keeping me honest about that. Some levels had to be redesigned from scratch 3 times before they felt good to play.

All of the levels are designed in a specific style called “kaizo”. Like an obstacle course, there is a very narrow path to progressing through the level and any mistake means starting over. The levels are brutally demanding by design. This hack is one of an enormous body of work developed by the Super Mario World community since the early 2000s. It feels good to be part of the kaizo artistic tapestry.

The boss battle at the end was by far the most difficult part to make. Written entirely in 65c816 assembly, the learning curve was steep. The whole thing took 6 months – about a third of the total development time of the hack. I am deeply proud of the result, and now possess a more intimate relationship with memory management than I ever would have hoped to have.

I host the code for this bossfight on github.

You can also download the hack to try it yourself on smwcentral. You will need a Super Nintendo emulator setup. Warning – it’s not for the faint of heart!