Hi there :)
Pros
Nice idea - preserving nature is always a huge plus for me
Fairly detailed spell casting - a small learning curve, but the descriptions were clear enough
Pretty setting
Beautiful colours and attractive sprites
Cons
Invisible walls - couldn't access a wolf fang in a small clearing among the trees despite my path being clear, and it was right there in front of me
Unclear as to efficacy of spells - my plants were dying really quickly despite me raising their speed of growth, toughness and size to 443 or something
Not as much interactivity with the surroundings apart from pushing animal sprites around and interacting with the casting pillars
Cleansing the corruption - unsure as to what was happening - At first, it caused corruption of the relevant woodland animal/plant, then there were 0 indicators of corruption (no purple) on the indicator, but I could see corrupted wolves and plants - and all three populations were dying really quickly.
It certainly needs quite a lot of work, and more direction. I assume the full game would give the player much more to do and the programming would be polished up.
I look forward to your next update, and thank you for putting your idea into practice!