This is addictive. Everything can be combo-ed, it's incredibly satisfying.
Edit: Some descriptions are a bit misleading, though.
The Druid's Growth says "...increases by X when other cards are played this turn". It's hard to identify at first glance if that means "increases by X each time a different card is played this turn" or "increases by X once if one or more different cards are played this turn".
The Druid's Root says "...increases by X for each card played this turn". It's not clear that the card it is referring to is "this card" (the Druid), and not "any card".