You might want to look into Zig, which has most/all of Hare's features, supports a wider range of platforms and OSes (Hare only does Linux+FreeBSD), and has metaprogramming in the form of comptime expressions (unlike Hare, which has no metaprogramming at all) while being pretty widely considered to be an "easy" language to learn (and everyone I've heard talk about it has said that it's far easier than Rust).