Last week, OpenAI unveiled the GPT Store. It’s a service, built into ChatGPT Plus, that lets you find and use custom versions of ChatGPT created by . . . well, anyone. And they can do anything that GPT-4 can do, including generating DALL-E images and interfacing with third-party services via plugins.

OpenAI calls these user-created chatbots “GPTs.” The ones it’s currently highlighting convey the breadth of what’s possible: There are bots for finding nearby hiking trails, learning to code in various programming languages, searching academic papers, and requesting book recommendations in a particular category. But OpenAI is getting ahead of itself in calling the GPT Store a “store.” Creators can’t monetize their bots by charging for them—the company says that’s coming—and most of the amenities familiar from Apple’s App Store and Google’s Play are missing, including ratings, reviews, and popularity charts.

Then again, it might be a tad premature to treat these bots as equal to apps. In my early perusing, I didn’t find any custom GPTs I’d be willing to pay for, in part because they suffer from the same limitations as ChatGPT itself. For example, when I tried the book recommendation bot, it made up some of its picks. The Canva GPT turned out to be an inefficient middleman between me and Canva’s own site; a logo designer spewed gibberish rather than the text I specified. There’s also some sketchy stuff in the store, such as bots that promise to create text that plagiarism checkers can’t detect.

None of that discouraged me from seizing the opportunity to create and share my own GPT. As OpenAI claims, it’s a simple process requiring no coding skills, and the hurdles to getting something published in the store are minimal. Judging from some of what’s in there, maybe they’re too minimal, but I still wanted to give it a try.

I also had—dare I say it—a nifty concept for a custom GPT. A while back, I fell down a ChatGPT rabbit hole by having its AI generate text-based adventure games, akin to the ones I played and wrote as a high school student in the (gulp) early 1980s. ChatGPT’s adventures were surprisingly addictive. They also neatly sidestepped some of AI’s idiosyncracies. After all, in a role-playing game, a vivid imagination is a feature, not a bug.

I called my new adventure-generating GPT Advent.ai. Over a few days, I trained ChatGPT to mimic the terse interface of the old games I loved. I set things up so the player could select the setting and theme, or ask the bot to suggest some options. I put in an “I’m feeling lucky” button that instantly drops the player into a game chosen by AI, and added optional DALL-E graphics rendered in an appropriately blocky style.

Getting my bot to comply with my instructions taught me a lot about crafting effective ChatGPT prompts. You can’t get the AI to do exactly what you want every time, even when it seems to understand: It’s a little like collaborating with a talented and creative partner who can also be sloppy and inattentive. But playing the games it generated, seeing what went right and wrong, and then tweaking my instructions got me much closer to my vision than I originally thought possible. I expect my other interactions with ChatGPT and its bot brethren to improve as a result.

If you’re paying for ChatGPT Plus, you can try Advent.ai for yourself. I crave feedback; all I know is that it’s been accessed 80 times so far, and even that modest figure might include me playing my own games. Still, I’m happy with the results, and take the fact that several other folks have published vaguely similar GPT game generators as a sign that there’s a critical mass of users who might care about my brainchild.

Regardless of whether Advent.ai gets any traction, I recommend the bot-building exercise. It’s like a crash course in AI prompt construction that also happens to be an entertaining way to spend a few hours. I do hope that OpenAI beefs up the GPT Store into a serious marketplace. But for now, the fact that it’s still a rough draft in search of killer apps means that nobody should be intimidated by the idea of joining the fray.