My favourite pokemon RPG out of the 2 i have; yellow and this.
251 pokemon was more than enough. 7 year old me went mad and played this game for 400 hours. And i gave up after 248 pokemon...3 more to go, but i could only get them through complicated trading etc..i think i needed mew and 2 other retro pokemon.
The graphics were hugely improved from the previous gereerations, and could keep your bicycle in the select button quick open type button.
Without collecting all pokemon the game lasts for a good 30 hours or so.
Heres my terrible story: I utrned on my pokemon after 2 years of gathering dust and all the data had been wiped:400 hours of hard labour gone like that... I then cried for 400 hours...