Magic Bean and the Penguins

You are a magical bean tasked with cleansing your luscious green walkway of pesky penguins! Launch your barrage of magical missiles and craftily place your runes to get rid of this menace! 

Your magic circles double as both offence and defence, shielding you from the penguin blasts. Sometimes offence is the best defence, but don't get caught off-guard! 

Controls:

How many can you take down before they take you down?