This is really good.
Level 14 has a solution where f3xd3, d3xd4, c6xe5 takes out _all_ the pieces and leaves the stage empty. An empty stage I suppose doesn't count as having one piece left? I suppose that's intentional, but it feels a little weird looking at the empty board and having to hit the reset button. :)
And on the flip side, Level 37: having a bomb left I guess counts as a piece?
Really lovely game. I think levels 47, 48, and 50 are my favorites.