You are a poisoner trying to kill all those pesky plants in your empty garden plot. Click on plants to destroy them. You can summon Agents who poison plants for you, but they only live for a limited amount of time. You can also buy flask upgrades to decrease your reload time. Unfortunately for you, the plants are speeding up, and you can't stop them forever... once the plants surround the evil poison vat in the center, you lose.

pro tip: after around three flask upgrades, they no longer have any significant effect.