This is an absolutely PHENOMENAL puzzle game, mixing Super Puzzle Fighter 2 Turbo-style "color-match-and-bomb" pieces with Tetris-style "complete-a-row-to-clear" pieces was a stroke of genius. I can't stop playing this. The only thing I could really even ask for would be a head-to-head multiplayer mode.
Just finally completed Miracle Worker difficulty after about 40 tries or so, then on Endless Mode cleared all 5 difficulties on the first try and looped back around before just completely screwing up and dying.