Selkie's Moon

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  title screen

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  dialogue

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  bullet cancel with sword

Inspiration

I was inspired by 2 things in particular. One, I recently read a really good story that some people might recognize this is a barely disguised fanfic of if they've read it too, and two, I really like CAVE's shmups.

What it does

It's a vertical scrolling arcade shooter where you can swing a sword that absorbs bullets into a 'berserk' mode. There are also dialogue segments and a functioning menu

How we built it

I decided that I wanted to specifically experiment with agentic AI, so I wrote comment scaffolding and instructions to Codex and let it generate a lot of the specific code that went into the GameMaker project.

Challenges we ran into

There was at least one moment where what I wrote collided with what the agent wrote, because the computer's currently checked out git branch is where both of them were going to. To be able to write code on another branch at the same time would end up requiring another computer.

Accomplishments that we're proud of

We managed a full game loop, story, boss, stage, etc. in a very limited timespan without using prior libraries.

What we learned

GameMaker isn't a very good IDE for specifically AI agents to work with because of all the .yy files and IDE mess it generates everywhere, and the speed at which AI agents actually work isn't all that quick, so for many of the less "tedious and widespread" tasks I likely could have done similar work in less time. Between that and the issue with branches, I'm not certain I'd want to use it for everything like I attempted to do with this. The project was a bit too high scope for a single person to begin with, so I think I'd want to lower my expectations if I were attempt this again.

What's next for Selkie's Moon

I've built it in a way that should be extensible enough to build into a full-length game. The specific spawn appearances, bullet patterns, etc. aren't necessarily reusable, but the general framework is, so I'll likely keep building on it because I do want to release a shoot-em-up as a commercial game.

Built With

• codex
• gamemaker
• gmtl