I played level one on normal and spent most of the time wondering if I had accidentally clicked endless. I like this game but there is no way I will play the same level for that long. Especially for the tiny amount of resources you get afterwards. I'll be keeping an eye on this game for updates though.
It is bad enough that most of the game is spent methodically sliding every element over every other element because there is no discernible logic behind most of it, but then you are forced to start over half way through when new combination become available with the old elements.