Flying Cactus or Engineer:
When playing as the Cactus, stand on the edge of a tallnut barricade, or the edge of a wall, and press the appropriate button to activate your drone. Fly beneath the vantage point where your Cactus is positioned and from there ascend to position the Cactus on the flying drone you are controlling. You can fly up to a roof or other high elevation, reaching areas that would otherwise be unavailable to that class. A similar technique also works as the Engineer with its drone, though not as effectively.
Infinite coins exploit:
Play Garden Ops mode as the Sunflower on the easiest difficulty setting and select any map, although Garden Center works the best. Proceed through the first wave without using any potted plants at all, until only one zombie remains. Once this occurs, quickly plant a Scaredy Shroom plant and lure the zombie over to it when it is scared so it starts to eat it. Now start healing the Scaredy Shroom using the LB ability, which will quickly generate coins to the tune of about 20,000 per hour, as long as you keep it going. You can even do this while you step away from your console.
Slender Man Easter Egg:
Go to the backyard of the Zomboss Estate map and look carefully beyond the thick tree cover forming the boundaries of the map.
The Zomboss Estate is part of the recently released Zomboss Down DLC expansion. Don’t worry, it’s totally free!
Look in the forested section to the left of the graveyard. He’s pretty far back behind the trees, so he can be a little tricky to spot, but he’s there!
Slender Man is known for his penchant to hang around the woods. Thankfully, this version just sits still. He won’t chase your plant or zombie when you turn away.
Slender Man is so chill that he’ll even let you shoot him. Carefully aiming between the trees, you can peg Slendy with a few rounds. But, if you try to fly in the sky and rain death from above, it looks like the suited figure simply disappears.