I ran RV32 core on FPGA, it was useful but painfully slow. Does it really have only 32 GPIO? No DMA?
The core provides (depending on configuration) ~0.9 coremarks per MHz.
The base core has 32 GPIOs (32xinput + 32xoutput) and no DMA. If you need a DMA or more GPIOs you can attach them to the Wishbone/Axi interface.