Had master trainer as a kid. It was a lot of fun. It's not overly complicated but my friends and I still play it to this day with a slightly modified rules to make the npc elite 4 battles a bit harder. Pick is my own, I laid out some of the pieces.
You basically adventure across Kanto, you encounter and battle random wild Pokémon, catch them, trade with other players, evolve them if you get lucky, and then go challenge the elite 4 and even capture mewtwo and the legendary birds if you are lucky. Still a very cool and nostalgic game for me to this day. I'd recommend. I have my own copy still (Pic included) but not sure what it would cost to pick up today.