Magika was innovative, though I didn't like it.
Spamming eart+fire combos was the quickest way to deal threats 9 times out of 10. Tons of combinations, but when you don't need 99%, that makes typing the combos opposed to hotkeying just an added inconvenience.
Still innovative.
Next best innovation is Portal 2, which merely expands a little on the old formula, with gels.
It's a poor showing this year.