Hi AI folks!
I've been doing gamedev as a hobby for around 10 years, and I'm finally getting to my first ever Steam demo! This video is one year of development squeezed into one minute.
The game was fully vibecoded (Claude Code and Codex), but it wasn't an easy ride. I'm a software developer with 15+ years of experience. AI can do complex things very fast and save you a ton of time, but it still needs to be guided by experience and good planning.
Some numbers after one year: about 500k lines of C# in Unity, roughly a quarter of it is tests, over 15,000 prompts and 840 commits.
Some tips I came up with during development:
- Define future goals upfront. I'm planning a local co-op mode, so it's written in the rules and every feature is built with that in mind. Will save a lot of time once I will switch to this task!
- Build core systems early. I didn't have all languages from day 1, but right after prototyping I made a system for quick language integration. Every line in the game has a key and is never hardcoded in code or UI.
- Keep an index of your systems. Once the codebase grows, AI starts losing track of it and reinvents things instead of reusing what already exists. Make a separate index for mid-big features and push AI to read it before any change. Keep it short.
- Keep a list of repeated mistakes. If AI makes the same mistake again and again, write it down and add a rule to check that list before any change. This helped me a lot to stop going in circles. Keep it short.
- Use your voice. Maybe it's obvious now, but it wasn't for me at first. You speak much faster than you type, so AI gets more context. Make sure you have good voice recognition.
- Ask for tests with every feature and every bug fix. AI breaks old things without noticing. Tests catch it before you do. A quarter of my code is tests and I don't regret a single line.
- Fix the cause, not the symptom. AI loves to drop a quick patch right where the bug shows up. Make it find the root cause first, otherwise patches pile up and start fighting each other.
- Make it show you. Review and read everything carefully! Some people ignore outputs or even checks of what id did. Sometimes it's just enough to read text carefull to see what AI did wrong, sometimes video/screenshot. Saves a lot of back and forth.
- Keep tunable values out of code. All balance numbers live in config files, and AI built me simple HTML editors for them. I tweak balance with sliders, no prompts needed.
- Run agents in parallel. I have several copies of the project, each agent works in its own, and a shared task board keeps them from stepping on each other.
Hope it's helpful! Happy to answer questions in the comments.
Would really appreciate it if you wishlist game on Steam
Thanks for reading!