Apparently the devs posted about why the mag stuff like reversed on the steam forums. The short answer is that if they made opposites attract, then there just wouldn't be very many possible puzzles. Here is the post:
Hello, your question is totally legitimate, and one can ask why we didn't respect what everyone knows, even if many of us at the studio left school a very long time ago. Of course we would have wanted to respect the science conventions, but we couldn't and the answer why can be found at this link: http://cloud-2.steampowered.com/ugc/111
In this picture you have to attract 2 platforms and 2 cubes, and get them near your character, please note they are all together, flying in the air.
If we respected the conventionnal bipolarity of Magnets, this situation is impossible. We could still bring the two cubes and the platform we need, but with 3 times more operations, clicking, flying and waiting. Each element would have to be brought back independently.
Of course, one could say: "don't create stuff like this", but, In other words, the puzzles won't be puzzles, the game will be a succession of applying the same and only rule with 2 elements only, because, never, more than 2 elements would be able to "work" together at the same time, the third one will necessarily be thrown away or throw away the element of the same polarity if its magnetic field had an inferior power. We won't add any additionnal mechanic and we won't be able to increase challenge and difficulty in the game.
a Simple exercise would be to redraw it with "real" magnetic rules. It's impossible. I believe it's a perfect illustration of what bending the rules can do and what respecting the rules doesn't allow, in term of gameplay.
As the question is totally understandable from someone who didn't play the game yet, and as we are working on a demo at the moment, it's totally fair to ask for an explanation. But for someone who spent more than 20 minutes inside the game (time to reach this level illustrated in the screenshot for the expert gamers that most the reviewers are), questionning the non decision (because it's not a decision if you follow the logic above) of having same color attracts is, in itself, very questionnable and rise some questions that the politically correct person I am cannot express further.
Thanks for asking the question and we hope it makes things clearer, if my reply is too badly written, because my english is not good, there is an excellent reply from one player here
"There is a good reason for this. Suppose that this worked like normal magnetics where opposites attract, it would be impossible to have three objects all attracting to eachother (a mechanic which becomes important later). The problem is that these are monopoles; each object has only one polarity (green or red). Real magnets (at least those made from non-exotic elementary particles) always have both charges. While I would argue that a game that properly simulates magnetic monopoles would be interesting, it would have to be a fundamentally different game from this one. It is also worth pointing out that magnetic fields are (at scale) continuous (non-discrete) and infinite (they don't just stop at some arbitrary distance). Furthermore, creating a cylindrical field requires a sufficiently long cylindrical magnet (you can't have an aproximatly spherical object emit a cylindrical field). Really, you just have to treat the mechanics of this game as something entirely different from magnatism."