Rust wasn't made to replace C, C is to be there at low level and as a glue code for everything.

Rust was made to replace C++ because the language it's a behemoth, it tries to do everything and the syntax it's a Lovecraftan nightmare, full of legacy incompatibilities. For small games such as Cataclysm:DDA I'd use Go (and for system tools and internet services OFC) and for game engines Rust it's or even GC based languages (not Java) can do it well (C# with AOT).

Even Common Lisp it's fine (just look up Trial/Kandria) with SDL2/3 and/or OpenGL bindings (Vulkan ones should be somewhere). Pick SBCL for speed, learn CL, learn about SIMD and optimizations. It can beat C on performance.

https://www.stylewarning.com/posts/nbody/

EDIT: the bindings are cl-vulkan, of course.