Mr. Game & Watch had a few problem matchups, and he dominated in some matchups more than he really should have. However, both sorts of problems were mostly fixed by changing other characters, not Mr. Game & Watch
A few little abusive things on him were fixed, and a few little problems he had were resolved. Mr. Game & Watch cares far more about the fact that Balanced Brawl features a very wide stage list; this allows him to be in his element more than ever.
All around, Mr. Game & Watch is largely the same, but the way the game is opened up helps him out.
Balanced Brawl Bonus: Greenhouse Gas
Mr. Game & Watch’s jab is now more advantageous than before and reliably links to his rapid jab.
Other Major Changes
Back aerial’s distant first four hits do 1% less damage (but are the same against shields).