Cute little game! Smooth, soothing, overall a really pleasant atmosphere.
I'm all about simple puzzle games well-executed, and you did a really solid job here. I think the spark mechanic was an inventive take on the event theme that fits right in with some of the other puzzlers I've enjoyed here.
The music and art style fit the gameplay well and seemed to mesh together, too. I think my only really critique would be around the spark-transfer. The shift happens a little too frequently for my taste, and since you can't move in the intervening period that leaves both shapes stranded for large portions of certain levels, just waiting for either to catch the spark.
On the whole, though, I think you did a great job!