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.
Broken Base: There are some fans that are willing to at least give it a chance or actually like it, despite the negative outcry from a lot of them. Some are happy that Spyro's personality is supposed to be like his Classic Self.
Cynder broke the base again. Legend fans were quite pleased, Classic fans weren't. Many fans wanted a clean break from previous continuities...
Some Skylanders even break the base. Sprocket for example has some people hating her just because she looks "too human", while others think she's a refreshing change of pace in adding some diversity to the teams. Some merely dislike her because they already have her and they have to wade through dozens of Sprockets to find what Skylanders are available in the stores next.
Critical Dissonance: Fans were really not looking forward to it, and many are making a big deal about how little respect they have for the game or hope in its ability to sell. Critics, meanwhile, are often very warm to the new game, taking it for the toyetic kids' game that it is, and quite like it.
From Spyro's Adventure, we have Terrafin and Ghost Roaster who are really good at dodging, Hex who can set up a super-powerful wall while she safely fire away from behind it, and Boomer whose ground pound attack hurts a lot of targets at once and stuns.
From Spyro's Universe, Tech Skylanders are really good for the Sky Defense minigame, where their machine gun Limit Break can mow down multiple mooks with ease.
Self Fanservice: just check at Deviantart, you'd be surprised how much arts there are about naked Stealth Elf, often with very exaggerated curves when compared to the skinny action figure.
Hex got some of this too; werheas her actual dress is rather sober and cover everything but her face and fingers, you will probably easily find art of her in Stripperiffic goth attire with Absolute Cleavage, when she even wears something. And of course, don't expect her to have decayed skin or anything similar : they apparently forgot she was suppposed to be an undead.
It doesn't take long for Ninjini, Chill and Sprocket to get fan-serviced either. As a deviantART member once reacted:
"God dammit....you just cant stop yourselves, can you? Gotta draw EVERY HUMANOID Skylander like she's some kind of god damn porn star!"
Shipping: while the game doesn't provide any visible romance between the Skylanders themselves (due to their personnalities and relationships never being explored except in the biographies and trailers), this hasn't stopped the fans from already imagining some shippings. Aside from the obvious Spyro/Cynder due to them being based on Legend of Spyro, Flameslinger/Stealth Elf seems to have become quite popular (logically due to the fact both are from the same specie).
Even Les Yay have been imagined already, mainly with Stealth Elf/Hex.
That One Sidequest: Some of the Heroic Challenges can be a nightmare for certain characters. For example, Drobot's HC requires the player to kill 100 green Chompies while avoiding the purple ones (although you are forgiven if you kill just one). Thing is, there is quite a ton of the purples in the dungeon, and they are also aggressive. Good luck trying to complete this challenge with characters with ranged weapons (you can accidentally shoot a purple off-screen) or wide-ranged attack (the purples will gang up on you).
Any challenge marked "Warning! This can be tough!" has the potential to become this. Like Drobot's challenge above, these often require precision, destroying some targets while avoiding others; and some Skylanders are just no good at avoiding collateral damage.
The Woobie: Sonic Boom. She went to hell and back to find a safe place to have her eggs and some rotten wizard decides to put a curse on them so they can always return to their eggs after a short period, meaning she'll never see her babies get to grow up. This didn't stop her from teaching them to kick butt, however.