Well, about 5 or 6 of those are easy to get using logic. For the others, I even tried to pay attention to the colors of the walls each time I make a decision. There has to be a way to get the darkest shade for that color.
At this time there are no hints to the achievements, except their names. This is something that we discussed a lot: we didn't want the achievements to be too easily obtainable, but maybe they're a bit too hard...
Use Rabbit for 'Living Superball' and 'Right Is Wrong', Child for 'Memory Test', Skater for 'Planning Makes Perfect', and Lizard for, well, Çonscientious Lizard'.
 "Rudiments"){kind=icon}
 "Dasein"){kind=icon}
 "Golden Blocks"){kind=icon}
 "Diamond Puzzle"){kind=icon}
 "Kaleidoscope Reef"){kind=icon}
 "Medieval Shorts 2"){kind=icon}
 "Slayaway Camp"){kind=icon}
 "Cat in Japan"){kind=icon}
 "The Killer"){kind=icon}
 "Tangerine Panic!"){kind=icon}
 "GlowPuzzle"){kind=icon}
 "Hivex"){kind=icon}
 "Strike Force Heroes 2"){kind=icon}
 "Tesla8"){kind=icon}
 "Political Wings"){kind=icon}
 "Oh! I'm Getting Taller!"){kind=icon}
 "hitBox"){kind=icon}
 "Run 3"){kind=icon}
More will come yes :)