A game you'll play for a looong time!!!!

Man this was my first Game Boy Color game and I remember staying for hours and hours straight playing this game!! The graphics are simple, very very simple, just a few colors are used and the different colors are mainly for distinguishing the different towns that Ash Ketchum is going to visit. Maybe this is the game that I played the most in my whole life, I'm almost 100% sure that it's one of the Pokémons games for Game Boy Color because I played too much all of them, specially this one, so I guess this is it.
Prepare to go for hundreds and hundreds of hours of gameplay, I know I did! But why not, beside a terrific storyline and a very long game, you can still train your pokemons up to level 100, maybe go after the rare pokémons and why not go for 151 pokemons caught? And if you're really a pokemon maniac go for 151 pokemons on level 100!!! I believe this would be the 100% for this game! Surely not for everyone. This game is in my top 5 of all time for sure!