Pretty short and sweet, although at times it felt like I was able to get away with not really caring what I was doing since it seemed that even if I got a match-up wrong it annihilated both objects, so as long as I was ahead I could basically sacrifice some to finish out the level. Not a huge deal, but it felt a little odd.
I was also confused about what the rules for the AI movement were, as others mentioned. It kind of worked out but ultimately made it feel more random than puzzle-y.
All that said, it still came together reasonably well, so nice job!