Very nice game from the "graphical programming" genre. For the jam it is OK as is, for further development I have the following suggestions:
1) At least a readme file that contains what is explained above here, because just 'as is' the game is not discoverable. Much better would be an ingame explanation and tooltips what the different brains do and 'how the game works'.
2) As Taupsi said, some means to continue playing the game from where one left of. Minimum would be some way to select some level no XXX, better would be if the game saved which levels I already solved and would present me with a seletion screen where the solved levels are marked (say green) and the unsolved are red (or may open/closed lock).
3) I initially did not realize that the 'exchange the colors around the rainbow' brains come in two versions (rotate clockewise and counterclockweise). Maybe inside the ring of colors there could be a curved arrow that goes (counter-)clockwise to make players understand that, because the current symbols are too similar to make the player see the difference, IMO.