Honestly reading through your comments, I couldnt reccomend Godot more - I'll just toss some bullet points below.

• GUI tools with lots of tutorials
• Basic 2D and 3D rigid body simulations
• Very extendable if you know C++ or rust
• In house python like compiled language deeply engrained into the engine, which is surprisingly fast
• Cross compileable to most devices, but honestly the engine itself runs on all devices I use so something like syncthing makes dev incredibly portable
• Ecosystem is only growing by the day, most tutorials are game dev related reasonably but still cover most topics one could need
• Basic GPU compute support if that's your thing

Theres some things its not yet perfect at, like the web export could be better - and in depth things like minimising copies between CPU and GPU might not be as fine grained as hardcore devs would like, but if youre coming from mathematics and python it'll fit like a glove.

Just for an anecdote I wrote a basic particle simulation in gdscript that was HORRENDOUS for performance, 200 particles all calculated the per frame force of attraction to every other particle then summed it; whole thing ran at 80 fps even on my phone