Huh. Never would have guessed. I am sure there were many “fancy” effects in the game, but during my playthrough, it all felt like it would have been achievable on a SNES.
I am not familiar with either Rust or the Switch, so maybe you can enlighten me: why would a Rust game be challenging on the Switch?
As long as you have a good C ffi (which Rust has), shouldn't it be quite easy?
Or is the Switch more similar to Android/iPhone where you cannot (could not?) run native code directly but have to use a platform specific language like Java or Objective C?
AFAIK some (all?) console vendors require you to use the compiler toolchain from their SDK to compile your code. So unless the console SDK includes a Rust toolchain the only way is to somehow translate the Rust code to C or C++ and compile that with the SDK compiler.
Maybe if the console SDK toolchain is Clang based it would also work to go via LLVM bitcode instead of C/C++ though.
As flohofwoe pointed out, you are limited by the console vendor SDK, the compiler toolchains, and everything required to target their OS, linker, API, ABI,...