You can get a proper C compiler in 2KLOC [or under 5Kloc of assembly https://github.com/oriansj/mescc-tools-seed/blob/master/x86/... | https://github.com/oriansj/mescc-tools-seed/blob/master/x86/...] Covering things like gotos, inline assembly, structs, unions, arrays and dozens of types and primitives.

Oberon doesn't provide much advantage over that.