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.
Complacent Gaming Syndrome: If you don't feel like playing around, chances are you're just going to stick to one or two reliable objects. Wings. Chainsaw. Rope. Especially since most objects in a single class largely have identical functions.
To drive home the "a lot of things work exactly the same" point, Abridged Vegeta managed to clear several puzzles in Unlimited using only Shoggoth as a Running Gag. Need to save a kitty? Here, Shoggoth. Need a present for your grandkid? Have a miniature Shoggoth. Class pet? Have a little tiny Shoggoth.
Critical Research Failure: The Unlimited challenge "The Butterfly Effect" has you getting rid of a butterfly so as to prevent chaos in the future. Anyone remotely familiar with the original A Sound of Thunder would know that killing the butterfly is exactly what you don't want to do.
You can console an orphan with "no one left" by giving them a dead mom in Unmasked.
Fridge Logic: You can run into this when comparing different summonable objects on nearly any sort of scale. Like how ants are larger than grenades (either those are the tiniest grenades ever, or huge fricking ants).
Some objects don't do things or interact the way you would expect.
You can stop those bomb-spawning pipes by just putting an IMMOBILE INVINCIBLE BAR right beneath it. Heck, INVINCIBLE is a Game Breaker in itself.
The BOMB DISPOSAL EXPERT will now just disappear the bombs instead of blowing them up like in Scribblenauts 1. Make him TINY INVINCIBLE FLYING DIVING and you can clear away any minefield easily.
If you make a BLOB, it can only be killed by fire, immune to anything else (besides OHKO destroy-everything items). It managed to kill GOD, DRAGON, HYDRA, and DEATH three times apiece, and fight Maxwell to a standstill. On the sandbox screen.
This is a really long one: Make an engine, make 2 chains, attach the chains to the engine's sides, pick up the engine, and move.
Vampires are indestructible unless exposed to one of their classic weaknesses (i.e. Garlic, Cross, Holy Water, Vampire Hunter). Starting in Super, they can be killed through other methods, but it takes lots of time to do so.
In the sequel, the adjective "CANNIBAL" or "CANNIBALISTIC", when applied to an object, will be able to destroy anything. Literally. Even Steel Doors and Spiked Steel Balls, as long as any adjectives that apply to the real one follows "CANNIBAL." And if you want to add adjectives, put them before "CANNIBAL".
The armed remote control car or armed remote control helicopter. You can't use adjectives on yourself, but you can use them on either of these and then directly control them. They're capable of doing anything you can (the armed adjective is necessary to pick things up). And even if they do fall in lava or something you can just make more. You cannot control them in Unlimited, but you can apply adjectives to yourself.
In Unlimited, you can apply adjectives to anything already on the field, including Maxwell.
In the first game, you can use the same item multiple times in Challenge Mode by putting anything and a space before it. This doesn't work in later games, since they have adjectives that actually do go before the word. Doubles as a Good Bad Bug.
Another Good Bad BugGame Breaker is in levels that are constantly spawning something that impedes your progress. For example, something that's constantly shooting bombs. Spawn something big over and over and over and over and it will fill up the ink meter, causing no more bombs to be shot either.
For some strange reason, if an ox is summoned, ridden, and then "used" on something, it will shoot high-velocity buttermilk at whatever it is used on. Probably unintentional. Unintentionally hilarious.
The @ method in Unlimited, which grants access to objects not normally available. Examples: Gender Blaster and Monster Gun (two rays that change NPCs into the opposite gender and a random monster, respectively), Maxwell and Lily's parents, and different types of magic. Here's a video showing how to perform the glitch.
And there were many complaints about the controls, especially for movement.
Another complaint is that many items won't work in ways you think they will. Want to get an large animal across a lake using a sail boat? Good luck getting the animal onto the boat with the sail in the way. You ultimately end up using the same reliable items over and over.
It's Easy, so It Sucks: A common critical reaction to Unlimited, where almost all tasks can be solved with obvious everyday objects.
Love It or Hate It: Scribblenauts Unmasked. You either like it for enabling you to interact and play with nearly every DC Comics character, or you loathe it because of its stunting of creativity and lack of sensible logic when it comes to the puzzles.
The ESRB page created several, including "Steak can be attached to a baby to attract lions."
Mood Whiplash: Scribblenauts Unlimited carries a wonderful, children's book message of using your powers for good. It's rather jarring if you spent the game finding interesting ways to kill people, or even if you completed the puzzles in... unorthodox manners.
Polished Port/Porting Disaster: The PC version of Unlimited has elements of both. On the one hand, being able to type in words with the keyboard is a godsend. On the other hand, the user interface is basically unchanged from the Wii U version, there are minimal options for optimizing graphics, and if you get a framerate of less than 60 FPS, the entire game will slow down to compensate. That being said, it's still far from broken and quite enjoyable in the long run.
Scrappy Mechanic: Unmasked saddles you with a 50% penalty if you summon the same item or adjective more than once in one level. This can get annoying when you have to cycle through several different forms of flight mechanics, ropes and such to drag things, and so forth.
Sidetracked by the Gold Saucer: The title screen sandbox mode is all you need to have a good time. Everything beyond tapping the "START" icon is just a bonus.
Spoil At Your Own Risk: A massive GameFAQs crackdown resulting from an early release, in which hundreds of topics were moderated for discussing gameplay before the street date.
That One Level: Constellation 8-5 in Super Scribblenauts. It gets worse when you see that it's an ADVANCED level, meaning it's one of the levels you have to complete three times in a row using different words each time to get an achievement.
To elaborate, the premise of the level is that you have to get the key to the gate behind Maxwell's starting position to free the princess. The key is on the other end of a hallway filled with boxes stacked on top of each other, chandeliers, and a sleeping dragon in the middle. Touching any object will almost certainly knock it down and wake up the dragon, and of course touching the dragon will have the same result. You also can't spawn anything to kill the dragon, as the dragon will wake up anyways. The only solution is to spawn wings or a similar object and carefully fly all the way to the key, then all the way back to the gate, which goes against the game's usual tendency to encourage the player to be creative.
Viewer Gender Confusion/Samus Is a Girl: Samurai, Ninja, and Clown are FEMALE. [[spoiler: The reason we know this is because they turn into Goddesses when fed Ambrosia. Anon wlll also eat Ambrosia, but will not change into anything, and will just stay Anon.
Villain Decay: It's hard to take Cthulhu seriously when it's tied to a tree, under your mind control and crouching beside you like a loyal puppy.