Very smoothly executed game that I enjoyed playing. I expected more of a clicking-squares / match / memory type of game at first, but enjoyed the maze navigation / rescue and escape game.
Pretty diabolical for how straightforward it seems. The mine explosion sound is perfect for creating a tense environment of anticipation / surprise.
If you wanted to take this game up a notch on the frantic / apprehensive scale, you could put some time pressure on how long players can "take in" the initial screen before they begin to move, by doing something along the lines of, say, having the vision begin to fade in and/or have the children start to have panic attacks and vanish so they can't be saved that round. Or dim vision further the more children you pick up. Or add heartbeat or other background noises as you go along. Not sure if you want to take the game in any of those directions, but it would seem to lend itself to that.
Perhaps there could be different "mines" (sets of stages) of varying difficulties / pressure.
A possible game mechanic to add if you were up to it, you could also make the player's board move / parallax slightly in response to moving the hero. By that I mean, say a 10x10 map would be centered in the screen with about two game-square distances between the edges of the board and the edges of the actual flash screen, when the player's hero is in the middle of the board. But as the player were to move around, say to the bottom-right, the 10x10 board would then shift up and left until the top-left square would be nearly adjacent to the top-left corner of the game screen. Similarly, moving to the top-right corner would shift the map to the bottom-left, etc. The biggest two reasons this might be worth considering, are (1) player immersion, and (2) it's an eloquent way to get around a simple cheat for this game of players posting small stickies / post-it note type papers on the physical computer screen just visually mark mine locations to avoid.