If you want a stable, hilarious, single-type challenge that replaces Kanto with a Sciuridae paradise, look for the and apply it to a clean Fire Red ROM. Avoid any file that is pre-patched and exactly 16.3 MB claiming to be the "original 1636" – those are often bait for malware.
You're referring to a Pokémon ROM hack! 1636 Pokemon Fire Red Squirrels Rom
Also, legal note again. It's important to remind users that downloading ROMs without owning the original game is illegal. The report should not provide download links, but encourage purchasing the original games and using hacks ethically. If you want a stable, hilarious, single-type challenge
The Squirrel didn't answer with a cry. It pointed its tiny paw toward the Indigo Plateau, where a giant, golden acorn pulsed atop the Pokémon League building, casting a shadow over the entire region. The reign of the 1636 had begun. first Gym Battle Also, legal note again
The Squirrels hack replaces in FireRed with squirrel-like designs while retaining the core gameplay loop.