I was able to get all the quests done without a walkthrough
This game is NOWHERE near one of the hardest puzzle games on AG (the SHIFT series were harder) and none of the quests were hard (Try to get the quests in "Give Up". THAT'S hard)
It just takes some brain power and some memory to beat these levels.
And i didn't misread the 2-5 one. Once you beat the level before when you were completing the game and you do the level again for the quest, that one turns from sort of difficult to VERY easy.