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.
Eternal Star in the original Mario Party. Going around a broken star, battling mini-versions of Bowser for Stars that they STOLE from you, while Awesome Music plays? Oh yeah!
Horror Land from Mario Party 2 and Waluigi's Island from Mario Party 3 as well. The former has an extensive day/night feature and Big Boo who can put you miles ahead of the rest but reaching him is risky. The latter has many tricks and traps that weren't needlessly unfair, including one in front of Game Breaker Boo, as well as an island that shifts its spaces. Bowser Land from 2 is also a pretty neat board, as the ? Spaces do many different things depending on what's close to it (which was the first time this happened in a Mario Party game), and the Banks loaned out money, instead of depositing them, meaning that you had to avoid a huge payload instead of trying to get a jackpot.
Base Breaker: Although most are happy about Rosalina's Island Tour appearance, others aren't happy about her not being playable.
Bite The Wax Tadpole: The "Payday" fraction of "Payday Waystation" in Mario Party 8 sounds embarrassing to Brazilians, as it is pronounced just like "[I] farted" in a very vulgar way.
Also, Panels of Doom/Panel Panic from Mario Party 4. You're standing on one of nine numbered panels that crumble away into a void based on numbers rolled by a Dice Block. If your number happens to come up, you're presented with an overhead view of your character plummeting to their doom while reaching in despair towards where their platform once stood.
Chance Time and Bowser's space, full stop! Even if you're the most skilled player who is in the lead, the chance of landing on the mentioned spaces will haunt you throughout the game, waiting to turn the table.
Also Crane Game from the first game. You’ll lose 1/3 of your coins if you’re dropped in the pipe, and God help you if a hard difficulty NPC grabs you.
The Scrappy: Many people hate Peach. One of the reasons is because she appears extra lucky as a NPC, regardless of difficulty.
Chance time! That doesn't even show up in Mario Party 8 or 9.
Control stick rotation in the first game qualifies. Many was the player who groaned at dismay when the roulette selected "Paddle Battle", "Pedal Power", and especially "Tug 'O War", which were annoying and difficult to win. Thankfully, after several players injured their hands trying to rotate the stick as fast as possible, forcing Nintendo to actually hand out gloves to game owners, no future games required you to do this.
Rapid-fire button smashing seemingly replaced this, being much more comfortable and less damaging to hands and control sticks.
Mario Party 9 having linear maps and all players travelling together in a vehicle is this to some.
Mario Party 4's Mini and Mega Mushrooms. The mechanic (replacing the skeleton keys from the previous games by having size changing mushrooms that open new paths — the Mega Mushroom allows you to skip board events, making it a borderline Game Breaker, while the Mini-Mushroom... allows you to go down smaller pipes while having a limited number on your dice) wouldn't be quite as bad if there weren't a number of mushroom spaces giving you the items, meaning that if you want to even have anything else in your pockets, you must use them to get rid of them, leaving you in either form most of the time.
Any minigame based entirely around luck - especially if they're Battle Minigames. You could potentially lose lots of coins just for being unlucky enough to pick the wrong thing.
After about a dozen or so Mission Pack Sequels, the series has gone up and down in quality game by game. The consensus seems to be that the first three are the "golden era" of the series, with each improving on the last (though there are some who prefer 2 over 3), while 4 is a low point. 5 and 6 are considered improvements, 7 messes it up again, and 8 is the lowest point in the series.
The ninth game seems to subvert this however by switching up its normal mechanics. Critic reviews manage to agree. Some fansdo not, however.
Island Tour also seems to have different mechanics as well.
That One Boss: Bowser Jr. Breakdown in 9, is hated for being a boss mini-game that's purely luck based. While Whomp Stomp and Bombard Big/King Bob-Bomb were also luck based, they at least had an element of strategy to them.note When playing with human players anyway. All Bowser Jr. Breakdown consists of is hitting a dice block, and hoping that you'll hit the right number.
The final battle of 7 was so hard that in Solo Mode, your progress on it was saved if you lost. Just hope that you didn't get to the 99th floor and your opponent gets the next shot at it. However, in the Free Play Sub, you needed to do it all in one go.
Mario Party 9 made drastic changes to the formula, causing controversy among those who were used to the traditional formula.
The fans went completely up in arms when 6 introduced the "gimmick boards" that steered away from the usual "star hunt" style of gameplay and would award stars through other means. Even though this was only done to give some variety between boards, very few were accepting of it, especially when it turned out it was here to stay in 7 and 8.
Island Tour seems to be a compromise between Mario Party 9 mechanics and those of the other games.
Bowser's Bigger Blast from 4 cuts out some of the suspense that Bowser's Big Blast had in 2, particularly the music, which no longer stops when someone is about to lose. Then again, it's a bit speedier than the original.
Unfortunate Implications: One of the duel boards in Mario Party 3 is called Blowhard. Okay, it's named for the fan in the middle, but still.