Hi, I'm the author of the compiler.

All backends supported by LLVM should be fairly easily supported by TinyGo. In fact, I've had the blinky example running on an Arduino a while back (8-bit, 2kB RAM, 32kB flash). There is nothing in the Go spec that requires a 32-bit system, just like there is nothing in the C standard that requires a 16-bit system (ints are at least 16 bits).

The biggest obstacle is not the fact that it is 8-bit, but the fact that it is a Harvard-style processor with a separate address space for code and data. I've added a section to the README to explain this. Also, garbage collection is going to be painful.