Only 32 opcodes, 8 of them special (can be used in th last 3 bits of a kind of 18-bit #VLIW word) versus 256 opcodes of #uxn

#varvara offers much more high level i/o, F18A has 4 interchip ports, GPIO, A/D interface and SERDES, which can be used to build things like Ethernet for example.
varvara-fpga does not implement most varvara I/O features at all.

https://www.greenarraychips.com/home/documents/greg/DB001-221113-F18A.pdf

https://www.greenarraychips.com/home/documents/greg/PB004-110412-F18A-IO.pdf