I started dabbling with chess engines written in Nim (lots of bit twiddling but also interesting concurrency challenges) and found it delightful. Genuinely the most fun I'd had with a language for years. I think the combination of native power with light, accessible syntax and a simple mental model is very promising indeed. The fact that you also get JavaScript compilation seems great, although I've not yet used it. I have tried, and will keep trying, to fall in love with Rust because I do buy into a lot of its philosophy but just never get there.