Very nice work for how small the source code is, and this is a relatively good design for the language.

I will say to criticise that I started scratching my head when I got to the standard library. The functions should really just be C's standard library. I know there's lots of baggage but e.g. remembering that 'print(s)' will print with a newline and 'printn(s)' won't, this is just putting a barrier to entry that's not necessary. Sure, have some new functions for slices, but if you can help it use more conventional names from C.