* No user macros at all. Six fixed format! / println!-family macros expand at parse time. - Meta programming is incredibly important in rust.
* (unsafe is) Forbidden at the language level. No unsafe keyword in Gossamer source. std is safe-Rust too. - No low level programming then.
* No move semantics. Non-trivial values are heap-allocated, reference-counted, and shared by reference; primitives are copied the same as Rust. - Again, no low level programming.
Calling this rust flavored (or even a systems programming language) seems a bit bold.