To change the border start a new game and pause it. Then press B
Start to play Helmet on easy. Then lose all of your lives right away. Then hit retry. You will play as Wario instead of Mario!
Play any game using Modern mode and earn 1000 points or more, you will be able to choose Very Hard mode/Star mode by choosing that game, highlighting Modern mode and pressing 'up'
In order to add G&W consoles that were showcased in the first Game & Watch Gallery museum into Game & Watch Gallery 2 museum you need two consoles and a link cable.Connect both consoles and leave the first game in the title screen. Go to Note Board in G&W Gallery 2 and read The Museum letter. Press Start while reading the letter and the content will be unlocked (both games will show a message in-game notifying the successful link).Note: only the G&W that you have unlocked in the first game will be added to the second game. So you are going to need 1000 points in every minigame in order to get all 16 original G&W in G&W Gallery 2.