There are no 'cheats' as such for Pokemon Leaf Green. By this I mean no press up, down, left and you'll get soemthing.
But at Super Cheats we have an extensive collection of user submitted hints
, questions and answers (members can ask questions too!)
, walkthroughs and faqs
for Pokemon Leaf Green.
Many aspects of the game are on those pages, registered users can ask questions, and if you visit the questions and answers
page you'll see that many hundreds of questions have already been asked - and answered!
Maybe your question has already been posted.
On the questions and answers
page there is a search facility where you can search for keywords, so if your question related the Mew, just type Mew in the search box and you'll get all of the questions already asked about Mew.
Further help can also be found on our Leaf Green forums