Welcome to my guide for Pyramid of Doom. These strategies are fairly freeform. I recommend having at least half of the total plants for this guide to be useful, although early on, these can be used, if you're lucky. These aren't tested for levels past 30, but they should work beyond that point. All strategies are built to be used without any premium plants with 7 seed slots, both free shovel boosts, and 25 extra starting sun.
Strategy 1: Few Graves
Snapdragon (Vital for its ability to hit multiple zombies and/or graves)
Infi-nut (Prefered, Wall-nut or Tall-nut also work)
Grave Buster (Only if graves are in inconvenient spots)
Puff-shroom (Early defense, and can be used to damage/destroy graves)
Potato Mine (Only if you don't have the Puff-shroom)
Iceberg Lettuce (Early stalling; its Plant Food ability is useful later on)
Cherry Bomb (Filler and last resort)
These are the zombies to watch out for, since this defense has some holes early on.
If you're using this strategy fairly early in Pyramid of Doom, these aren't a problem, as there will be few. However, in later levels, these can appear fairly early; this is why you have the Potato Mine. If it's still recharging, spam Snapdragons and Spikeweed/Spikerock.
These guys are more annoying than anything. Since Grave Busters don't recharge that fast, the easiest way to deal with them, and the graves they raise, is to use lots of Snapdragons. If they appear late in your defenses, their damage will be minimal.
The second-toughest zombie in the entire Pyramid of Doom, Pharaohs will wreck your defenses if you aren't ready, and can survive two Potato Mines. Thankfully, they eat fairly slowly, so using Spikerocks and Snapdragons with Infi-nuts will neutralize them fairly easily.
The most dangerous zombie in all of the Pyramid of Doom, Explorers can destroy an entire defense grid in record time. Due to how this strategy is built, the easiest way to take care of them is Spikeweed/Spikerock. You might lose a few Infi-nuts early on, but their surprisingly fast recharge will make this just painful and not lethal.
Start off with a Sun-shroom instantly or a Twin Sunflower as fast as you can afford one. If you're willing to use unintended features, save and reload. No matter what, use a Plant Food on this plant. Try to get two columns of them. One column will work fine, but two makes this much quicker. Kill off the first few zombies with Puff-shrooms or Potato Mines, and use Puff-shrooms and Grave Busters to destroy the existing graves. Plant the first Snapdragon in a way that a one column gap is between it and your sun producers. Try to get a full column of Snapdragons as soon as possible, and get them behind Infi-nuts. Spikeweed/Spikerock should be planted first right next to the Infi-nuts and then further back. Try to get two full columns of Snapdragons before the level ends. Use Cherry Bombs if you have them when needed. Try to avoid using Power-Ups unless something goes wrong.
This strategy is able to fight Mummified Gargantuars, but only if you are willing to use unintended features. If you're not, you're in the wrong blog.
Strategy 2: A Song of Ice and Lettuce
Sun-shroom/Twin Sunflower (Same reasoning as in Strategy 1)
Bonk Choy (Improved synergy over the Snapdragon)
Winter Melon (Heavy hitting at long range)
Infi-nut (Same reasoning as in Strategy 1)
Grave Buster (Same reasoning as in Strategy 1)
Puff-shroom (Same reasoning as in Strategy 1)
Potato Mine (Same reasoning as in Strategy 1)
Iceberg Lettuce (Same reasoning as in Strategy 1)
Spikeweed/Spikerock (If you have space)
Cherry Bomb (If you have space)
The zombie threats are essentially the same, except Explorers are less dangerous and Pharaohs become the highest threat, primarily early on.
The very beginning is identical to Strategy 1, but instead of planting a Snapdragon, you use the Bonk Choy. Try to get at least one Winter Melon by the first wave. One column of Winter Melons behind Bonk Choys behind a standard defensive wall (Infi-nuts and Spikeweed/Spikerock) will be able to defeat normal levels, although tougher ones may warrant digging up a column of sun producers or Bonk Choys in place of more Winter Melons. As always, only use Power-Ups and Plant Food when needed (or, in the case of Plant Food, when you're full but one is dropped).