many of the illustrations are unlocked unlocked by fullfing specific conditions with certain characters during a 2-player match.Problem is:
1-got only one controller
2-got nobody to play with(and I can't even do 1P controller and 2P Keyboard because the game doesn't register two players that way...)

so I can't pretty much unlock these arts.If anybody has a save file with those gallery pieces unlocked,please share with us.