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: Sonic Rush Series
Anvilicious: The first game really shoves the "friendship" moral down your throat in the cutscene in the Last Story preceding the fight with the Eggmen.
Alternate Character Interpretation - Actually Marine has an inferiority complex and knows the other characters think little of her, so she acts proud and arrogant in order to appear tough and confident, becuase she's desperate to prove to herself and others that she's useful, ironically she'd be much more useful if she just acted normally.
Breather Level: There are a few candidates, but Huge Crisis from Sonic Rush is a remarkably straightforward (quite nervewracking, but low on bottomless pits) stage despite being quite late in the game. Even the boss is just a rehash of the Leaf Storm boss.
Also Blizzard Peaks. Not like Rush Adventure is that hard, but Blizzard Peaks is shorter than most levels before and both of the levels after it.
Another popular idea is that her world is actually an alternate future, in the same vein as the split timeline in The Legend of Zelda. It's basically what would have happened if Iblis didn't fuck shit up.
Goddamned Boss: All over the place in the first game, but especially the boss of Huge Crisis and how it loves to spam its missile attack.
The second game averts this by giving bosses lots of health (the first boss takes 20 hits to defeat) but they are almost always vulnerable.
Mondegreen: It's very easy to mishear the lyrics of the second game's boss theme as "We got fucked again." (You can thankHellfire Comms for that one)
That One Level: Again there are a few candidates, but the stand-out example is probably Altitude Limit from Sonic Rush, with its insta-kill lasers and tricky gimmicks, and quite a long run before reaching the first checkpoint. Night Carnival isn't quite as bad, but it gets bonus points by being the first level in Blaze's story (so you've got no chance to go back to earlier levels and grind lives, as you can with Sonic).
Sky Babylon in Adventure, especially Act 2. And the very Trial-and-Error Gameplay snowboarding/minecart missions to collect the flags in order, and you can't backtrack at all.
Don't forget the seventh Chaos Emerald stage in Rush. Randomly placed bombs, not very many rings at all, and the trick bumpers are hard to get to. Did I mention those randomly placed bombs?
Haunted Ship in Sonic Rush Adventure grinds you up mercilessly if you ever try boost too much using Sonic. However, it seems to heavily favor Blaze over Sonic as it's more vertically oriented, so it might not have this title as Blaze.
That level also includes fire traps, which Blaze is immune to.
The Scrappy - Marine for some. In fact, she even annoys the other three heroes by constantly reminding them that she's ship captain, and also for her 'get the treasure first, ask questions later' personality which often leads the four into trouble. Her horribly overplayed Australian accent in the dub doesn't help either. This results in Blaze telling her exactly why she can't come to the final zone with them.
Scrappy Mechanic: The rockets in Dead Line in Rush. They move really fast, but handle really lousy and get destroyed upon touching a wall. Merely tapping the control pad can send it at a very wide angle. And there's one section where you actually have to use it to get over a bottomless pit.
The balloons in Sky Babylon in Rush Adventure. Like the rockets described above, they control like crap, and they are destroyed immediately upon touching a wall. They're similar to the rocket pads from Altitude Limit from Rush in that they only go up, but unlike them, the balloons need a wide space in order to turn. What makes Sky Babylon That One Level for a lot of people is one section where you need to use it to evade a series of instant-kill lasers.
Some of the music in Rush sounds very similar to some Jet Set Radio and Jet Set Radio Future tracks, but that's because Hideki Naganuma did work on all of them. Of note is "Get Edgy", which many fans have noted sounds like "Let Mom Sleep".
Machine Labyrinth in Rush Adventure sounds like the Ritchie Valens version of La Bamba.
Tear Jerker: The ending of Sonic Rush, watching the video of Blaze returning to her home dimension was something indeed.
Woolseyism: Say what you want about Marine, but the English translation giving her an Australian accent makes sense considering all the koala NPCs.