Very cool little puzzle game! Very short in its current form, but that's understandable given the short timeframe. I'm also not sure I see the 'chain reaction' theme, at least not in its current form.
I think the bones here are really solid, though. I enjoyed thinking through what's there now, and I think with some additional puzzles, items, etc, this could really be something cool. The thundecloud at the end was a nice addition, and I could imagine more things like that leading to some really cool puzzles. Great job!