Comment by loh

Just for fun, I built a first person shooter game in UE5 from scratch using agentic coding. I've only spent a couple of months on it in my free time so far, and it isn't complete yet, but it's close enough that I could definitely release an early access version with another month or so of work. The most time consuming tasks have actually been tasks that agentic coding hasn't been able to help out with, like animations and mapping. The game is mostly written in C++ and sometimes the agent makes some bad decisions, but with a bit of extra guidance and being smart about my git commits so that I can revert and try again if necessary, I've always been able to make it work the way I want. I most definitely would not have been able to build this on my own in any reasonable amount of time.

FWIW it seems like it heavily depends on the agent + model you're using. I've had the most success with Claude Code (Sonnet), and only tried Opus 4.5 for more complex things. I've also tried Codex which didn't seem very good by comparison, plus a handful of other local models (Qwen3, GLM, Minimax, etc.) through OpenCode, Roo, and Cline that I'm able to run on my 128 GB M4 Max. The local ones can work for very simple agentic tasks, albeit quite slow.