Zombies walk in along the five lanes from the right. Stop them before they reach your house on the left. Each lane has one lawn mower that clears the whole lane once, but after that a zombie getting through means game over.
Sun: tap the falling suns to collect them. Sunflowers make more sun. Sun pays for plants.
Plants: pick a card at the bottom, then tap a lawn square. Shooter fires peas down its lane, Frost slows zombies, Wall soaks up bites, Bomb blows up a 3x3 area. Cards recharge after use. The shovel removes a plant.
Waves get bigger and tougher, with a boss every 10th wave. Survive 10 waves to win, then keep going for a new best.