These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Wario Land
Anticlimax Boss: After completing every level and finding every goal and treasure, Wario makes his way to the "Really Final Chapter", here he fights... The Giant Spear Man. Again.
Awesome Art: Pretty much the entirety of Shake It!/The Shake Dimension.
Badass Decay: In the first two games, Syrup's modus operandi was to attack Wario, rob him, blow stuff up, or some combination of all three. In Shake It!, it's to flirt with him and then steal his gold when his back is turned.
Possible Fridge Brilliance-induced justification in that attacking him head-on the first two times didn't exactly work in Syrup's favor. Using her brains and womanly wiles over brute force turned out to be a much more viable strategem.
Breather Boss: Multiple, but Beefne from the first game counts... you just attack him and then throw him off the platform into the instant death lava.
It was also because she was the first female Big Bad in a Mario universe game. (Yes, she predated Cackletta, the Shadow Queen, the Golden Diva, etc. by several years.)
Wario himself was one in Super Mario Land 2, which is what led to the birth of this series.
Even Better Sequel: Wario Land is considered a good game, Wario Land 2 is considered a better, and more fun game, and Wario Land 3 is considered one of the greatest Game Boy Color games of all time by some critics.
Fake Difficulty: All over Wario Land 2 and 3. When the hero can't die, all you can really do is annoy him. In particular, most of the bosses have a way to kick Wario out of the fight and make him start over... and over... and over...
Fanon: The games have never given Captain Syrup's first name, but everyone assumes it's Maple. It does have Word of Dante on its side, though, having been used in a Famitsu article.
Game Breaker: In the original Wario Land, the Jet Helmet allowed Wario to fly a certain distance by pressing B in mid-air. Wario keeps flying for a fixed distance (at which point it will fly downwards like landing) or until the player presses B again. But, double-tapping the B button caused Wario to stop its current flight and start a new one while still airborne, allowing him to fly as far as pleased.
The Debug mode from the first game (pause the game and press select 16 times) is much worse, as it allow you to manipulate which Wario you have and your number of lives, coins, hearts and even the amount of time you have.
Needs More Love: While a hit at the time, this series is underappreciated now — largely ignored in favor of Wario Ware, to the point of even being shafted out of Super Smash Bros. Brawl representation. Shake It! was pretty successful, but there seems to be no more Wario Land on the horizon. The series deserves more credit, especially games 2 and 3, arguably two of the most fun and creative platformers ever devised.
Special mention goes to Virtual Boy Wario Land. The Virtual Boy console was such a flop that most people missed out on this title. Consensus among those who did get to play it is that it was the best thing made for the system, and is long overdue for a rerelease — ideally on the Nintendo 3DS with its 3D capabilities.
Some of the enemies in Wario Land 4 are pretty disturbing too. In particular, several enemies in an early lake level (I can't remember what it was called) tend to have huge fangs suddenly appear on their mouths as they try to bite you. Especially that one that pops out of holes in the background. Dear god, that thing is freaky...
And back to Wario Land 3, the final boss fight, Rudy the Clown. Primarily because it's the one enemy in the whole game that can actually kill you.
In Virtual Boy Wario Land, the final boss is the "Demon Head," and if you ever wondered what Mr. Burns would look like if he turned into a demon, well, this is it.◊ Narmy? Maybe, but his introduction is freaking creepy, and that Slasher Smile ain't too pretty either.
Wario's "crushed flat" and "turned into a spring" transformations in 2 and 3 are pretty horrifying, especially when you first see them. It's one thing when that stuff happens to cartoon characters — quite another when it happens to "you" in a game.
Sequelitis: While by no means a bad game, it's generally agreed that Wario Land 4 is weaker than the previous 2, mainly because it makes Wario able to be killed again, there are fewer transformations Wario can go into, making every level a time-trial mission to escape before it explodes, and now making it mandatory to find every single treasure to beat the game.
And finally, the Shake King. His first phase isn't so hard, but his second one gives you a good idea of what Touhou would be like on foot.
To bring that point home, the Shake King's electric ball attack during his second phase combined with some of his other attacks turn the boss battle into a Luck-Based Mission depending on where and how they bounce, and if you die on the second phase, you get sent all the way back to the first phase. Hope you have enough coins for some recovery potions.
Uncanny Valley: Many, many bosses. Indeed, the clown bosses in the series hit the lowest point without even trying, with Rudy looking creepy, Clown-a-round looking really, really artificial and Chortlebot looking somewhat demonic. But then you've got the other bosses, like most in Wario World. The Winter Windster is disturbing. The Mean Emcee is disturbing. Brawl Doll... dear God it's disturbing looking like a plastic cupid doll with overly large eyes, and that's before it turns its head 180 degrees round while laughing. They probably look worse than characters from the Polar Express.
Unfortunate Implications: Wario Land 4 has you go into a variety of interesting, creative worlds... to set off a bomb which DESTROYS THEM COMPLETELY. Every single level.
They apparently get better, as you can reenter them as many times as you want. But it's a moot point, as the entire pyramid collapses at the end of the game.
Visual Effects Of Awesome: The hand-drawn sprites in Wario Land: Shake It!/The Shake Dimension look very nice — and that look didn't come easy. Wario alone has over 2,000 sprites!