Tarnation

You control a garden, using your mouse to plant colored flowers. Each color summons a different type of unit to defend the central seed. The moment to moment play is about quick selection and placement, directing your little army of sprouts and vines against the invading Tars. Your main goal is to survive all eleven levels, which culminates in a fight against a larger boss creature called the Mother Tar. The pacing is steady, but the difficulty builds in a noticeable way as more enemy types appear. It feels like a focused and slightly frantic game of botanic defense.