That said, "C" (C99 with benign bits of c11 required for modern hardware programming) is only the "less worse" compromise for a computer language: its syntax is already way too rich (I let you think about the beyond sanity computer language syntax out there, yep... even for currently hyped ones).
For instance: C should have only one loop keyword loop{}, finally a real hard compile time constant definition, no integer promotion, no implicit cast (unless void* or some generic number literals), probably explicit static/dynamic casts (but certainly not with the c++ syntax), sized types should be primitives and not the other way around (s32,u32,f64...), no typedef/typeof/generic/etc, but should include inline support for modern hardware architecture programming aka memory barriers/"atomics"/explicit memory unaligned access, etc.
The benchmark is a small team of average devs should be able to develop a real-life compiler in reasonable amount of time.
Ofc, the more the merrier.