Great game, took some time to learn all the spells, but when I figured it out it came natural what next spell combination will be.
Not without bugs, obviously, but I want to point them out, as maybe they're specific to my machine config. First of all text flickers on Safari, making it unreadable. On Chrome game runs fine, except that some of the effects and enemies are missing when you go to the second portals in Sun and Lun. Like after killing enemies in the second portal Lun portal they still shoot at you once or twice.
But overall I really liked how you need to keep track of a balance of dualities and how you solve puzzles with clever use of relevant spells.