Bought Yellow not long after it came out and it still works after 20 years. Currently just started my own custom challenge. If anyone wants to try it, here's a rundown:
1) Maximum of 6 active Pokemon.
2) Only one Pokemon of a respective type per game once caught. If a Pokemon dies(aka faints), it must be immediately boxed and you may not catch another Pokemon of the same type(Ex: Capturing Pikachu(Electric) means all Electric types are locked). Starter counts towards Active Pokemon list and locks that corresponding Type(Charmander locks Fire, Bulbasaur locks Grass, Squirtle locks Water and Pikachu locks Electric). Pokemon with dual typing may be caught but the Typing must be declared upon capture(Ex: Pidgey is Normal/Flying type. When caught, must declare if its for Normal or Flying typing. Meaning it would be possible to catch both Pidgey and Spearow since one would be for Normal while the other for Flying).
3) Gym Battles are on equal terms. For Pokemon Yellow, Brock and Misty are 2v2 Pokemon Battles, Lt.Surge is 1v1 while Erika, Sabrina and Blaine are 3v3. Koga is 4v4 while Giovanni is 5v5. E4 is full team due to rival having 6 at end. Non-participating Pokemon must be boxed prior to Gym Battle and any participating Pokemon must not be higher in level than the strongest Pokemon of Gym Leader.
4) HM Moves may be taught to active Pokemon while TM moves are restricted to the following condition: It must be a STAB move and be taught to a Pokemon that doesn't learn a STAB move naturally(Ex: Sandshrew being taught Dig). Otherwise TM's must be sold or boxed.
5) Potions and other items are self-found and can be used at any time. Liberal use of Pokemon Centers is permitted and recommended due to cap on Active Pokemon. May only purchase Poke Balls and Game Corner Coins(to exchange for Pokemon).
6) Evolutions are not permitted. Exceptions are Caterpie line, Weedle line and Abra to Kadabra. Eevee may also be evolved but counts towards Normal and w/e element it evolves into.
Any questions, feel free to ask me. This challenge means no Flash for Rock Tunnel(not like its 100% needed).
