Here's a random grab-bag of system stats. Let me know if you need anything specific (redacted for relevance):
Web Browser Firefox
Maybe more like 5-10 fps, but in the video I recorded, it drops to 1FPS once three tops start hitting each other.
It literally looks like the animated gif in the top left corner of this page.😅
It's really interesting that you chose to make your own game engine from scratch. That's literally the hardest thing to do in Game Development, and it usually results in years of wasted effort and developer regrets. One thing you gain from using an established engine like Unity or Unreal or Godot is hardened battle-tested reliability. If someone's using a 4 year old laptop with obscure generic parts from china and out-of-date drivers, that use case has already been encountered hundreds of times by the thousands and thousands of developers using the engine, and is usually long-since patched before you've even picked up the engine.
Now, you can spend hundreds of hours squinting at bad code and pressing the re-roll button until the RNG gods smile upon you and the markov chains manage to guess an answer that looks close enough to what you asked for that AI-bros with high-end systems won't complain too badly about it. Or, you can spend 5 minutes per decision squinting at the engine documentation, make all of the actual decisions yourself, not just the architectural ones, and, most crucially, pivot on a dime when something goes wrong, without completely regenerating everything from scratch and thus losing any institutional knowledge you'd managed to build up about how your own game works.
The downside is that you have to actually think about what to do, and then do it. Every step of the way.
The upside is the 90% of gamers who stay far, far away from anything with the "AI-assisted" tag will not only click on your game, but it might actually just work out-of-the-box on their equally-jank, barely playable devices. When it doesn't, you'll be able to talk to a person in the community or on the engine development team who knows the engine better than you, learn from them, and gradually improve your craft.
I'm sure the sunk cost is probably too great on your end for what I just wrote to change your mind, but I hope you'll think about it for your next project. Whether you were a traditional developer before you picked up AI, or you've been vibe-coding ever since you picked up your first computer, it's worth doing it yourself.
That said, I honestly don't know how I'd go about programming this. Who knows? Maybe this is one of those rare edge-cases where AI is actually the right tool for the job. Maybe there's a big database of Beyblade Math somewhere, and that was the only possible way you could have gotten the arena slope to feel just right to kids who grew up playing BeyBlade, or something. Now, most games fake their physics instead of actually calculating them. But maybe your game uses real physics under-the-hood. Maybe there's a good reason for that. I don't know. If that's the case, I'd love to hear about it. There's a part of me that's rooting for you, even though you're on the other side of the AI debate. I'm not sure why.