After being thrust headfirst into FPGA development thanks to the Analogue Pocket, my first from scratch creation was a gate level implementation of the original Tamagotchi toy.

The core, running on both the Analogue Pocket and MiSTer platforms, lets users re-experience the very first Tamagotchi from 1996 with accurate emulation, but modern features. The core has savestates (which is much harder to do in hardware vs software emulation), high turbo speeds (1,800x was the max clock speed I've reached so far), and more.

Learning more about hardware and FPGAs is something I've wanted to do for many years, and I highly recommend it for any programmer-brained person. It's a very slightly different way of thinking that has vast consequences on how you look at simple problems.