Plants vs. Zombies: The Final Showdown

 Plants vs. Zombies: The Final Showdown is a spinoff in the PvZ series. It is designed to be much harder than the regular games in the PvZ series, aimed at the experts of PvZ.

NOTE: The picture style is PvZ1, not PvZ2.

Description
Dr. Zomboss was defeated, the zombies almost entirely wiped out, but now, a new threat is here, a new leader of the zombies. We are losing the war with the Zombies. Your mission is to find and defeat their leader, but it won’t be easy. Crazy Dave and Burt will help you out, but there are new, tougher zombies. Some make the Gargantuars look like pussycats. This isn't for the feint of heart. Only the experts should try this game.

Areas

 * Campsite: The first two levels are a kind of tutorial, although nowhere near as easy as the tutorial levels in the other games in the PvZ series. Starting with Day 3, at least one campfire is located somewhere. Each campfire cannot be planted on, but causes zombies on top of it to lose 1nds of health every second. It also defrosts chilled or frozen zombies. Campfires can be damaged by plants (they have 60nds of health), but cold plants will do double damage and hot plants will do half damage.
 * Misty Pond: Now you get thrown into the thick of it. This stage is all water and it has fog (although it's called mist in this game), as well as being night-time. You start with five columns of Lily Pads in the first level (as you can't plant any more, you get Sea-shrooms before Lily Pads), but only two columns in the levels afterwards.
 * Icy Rink: Tricky, tricky, tricky. You have to plant in Flower Pots (you start with two columns), as plants can't survive on ice, and the Pots sometimes slide into an adjacent empty space because of the slippery ice. This only has a 10% chance of happening to each Pot every minute, but if you have lots of Pots, it's likely that they will slide quite often.
 * Dark Volcano: This is where it gets REALLY hard. This is night-time again, and the middle row is lava, so only a few zombies can go in that row safely, but NO plants can be planted in that row, making it hard to defend.
 * Doom Dungeon: You get captured and taken to a dungeon. You need to escape, but as the floor is stone, you need to plant in Flower Pots (you start with two columns), and there are only small windows letting in sunlight. Only 15 sun falls from the sky at a time and mushrooms fall asleep!
 * The Great Graveyard: The last full stage, tombstones block your shots like campfires did, but they also spawn zombies every fifth wave (that means every Flag and every wave halfway between Flags). This also takes place at night, making it even trickier. On top of that, this is where the hardest zombies are introduced.
 * Zombie Castle: This stage has only five levels, but all are very hard. You plant in Flower Pots (you start with two columns), and it's night-time, but the zombie combinations are deadly and lethal. Expect lots of failed attempts at the levels in this stage.

Stars, Gates and Level System
Explanations about the level and map system.

Stars
For regular choose-your-seeds levels, there are three goals: Don't lose any Lawnmowers, and two others which vary from level to level. You'll be told all the goals, even if it's your first time playing the level, and you get one star for each goal you complete. Complete all three on one playthrough, and you'll get three stars for that level. For special levels (Conveyor-belts, Last Stand, Save Our Seeds), you only have one star, which is for not losing Lawnmowers.

The other goals that you can get are:
 * Save up at least >insert number here< sun by the final wave.
 * Don’t spend more than >insert number here< sun.
 * Slay every zombie within >insert number here< seconds of it appearing.
 * Don’t plant more than >insert number here< plants.
 * Don’t lose any plants.
 * Don’t plant any plants that cost more than >insert number here< sun.
 * Don’t destroy any campfires (Campsite only).
 * Don’t remove any mist (Misty Pond only).
 * Don’t use any Sun Producing plants (Campsite, Icy Rink and Doom Dungeon only).
 * Don’t use any Mushroom plants (Misty Pond, Dark Volcano and The Great Graveyard only).
 * Don’t destroy any tombstones (Great Graveyard only).

Gates
For the gates that lead to side paths, you need to complete certain goals to unlock the gates, rather than collecting keys. However, there are also gates on the main path. The third, sixth, ninth, twelth and fifteenth levels in each stage have gates that block you from playing them, and these gates are unlocked by collecting a certain amount of total stars (in the entire game, not just the one stage). Usually, this will be more than 50% of the amount of stars it's possible to collect by that point, not counting side paths.

Extreme Mode
When you get all the stars on a regular level, you can earn a gold medal on top of that when you replay the level, as you get the option to replay in Extreme Mode. In this mode, Seed Packets take 10% longer to recharge, Zombies are 10% faster and do 10% more damage, and the waves are harder.

Unlocking Other Stuff

 * You unlock a Challenge Zone for a stage by beating level 15 in that stage.
 * You unlock a Survival: Endless mode for a stage by getting every star in that stage.
 * There are four Treasure Chests in most stages, which give you 1,000 coins and are collected after beating levels 3, 6, 9 and 12.
 * You get plants or boosts after BEATING a side path, not at the start of a side path.
 * If you collect every star and gold medal, you'll unlock a special bonus level in the Zombie Castle Stage! But I'm keeping details about that bonus level secret for now.

Recharge Timers

 * Instant: Not quite instant, it's 1sec. 1.1sec in Extreme Mode.
 * Very Fast: 8sec. 8.8sec in Extreme Mode.
 * Fast: 15sec. 16.5sec in Extreme Mode.
 * Slow: 30sec. 33sec in Extreme Mode.
 * Very Slow: 60sec. 66sec in Extreme Mode.
 * Ultra Slow: 150sec. 165sec in Extreme Mode.

Plants
^ - Battle style changed.

Soundtrack
Here I'll list the different music tracks I find which I think would fit well in this game. I don't take credit for any of this music.

Trivia

 * The game is similar to earlier versions of Plants vs. Zombies 2: It's About Time, with sun being worth 25 again, and the map design is similar too.
 * I copy-pasted the source from Plants vs. Zombies 3: Dimensional Travels and changed what I needed in order to make this page, cause I'm lazy like that.