That game was the best! The most challenging levels were Fire 10 (Bonfire), upper left, Air 12 (Tunnel), putting the right angle, and timing in Earth levels with more than 4 bombs. Like Rastille said, challenging, but not impossible.
There is a bug-like error. If you play on giant setting, yo have to reclaim 200 areas, but you have only 100. Please make the giant setting 15*15 or so.
Thanks!