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: Chip's Challenge
Complacent Gaming Syndrome: The vast majority of players tend to play the MS version over the Lynx version, mainly because its various glitches and design flaws make it the better version to Speed Run.
Teeth monsters, due to their habit of permanently going after Chip.
Walkers and Blobs, due to their erratic movements which makes them unpredictable.
Faux Symbolism: Levels 54 (Grail) and 142 (Pentagram). They're shaped after a cross and a pentagram, respectively, but they're otherwise normal levels.
First Installment Wins: Between Chip's Challenge and Chuck's Challenge. Knowledge of Chip's Challenge and its mechanics (both in the original Lynx version and the MS port) has risen dramatically over the years, and fans are still creating custom level packs to this day, most of which tend to be very well-designed. In contrast, Chuck's Challenge is mostly unknown, suffers from sketchy controls (at least in the iOS version), the built-in levels are fewer in number and are generally of lower quality than the ones in Chip's, and the user-generated levels are mostly terrible.
I Am Not Shazam: While Chip's Challenge does star Chip, Chuck's Challenge doesn't star Chuck; you play as Woop, playing through puzzles created by Chuck.
If you're in a level where an enemy is controlling the buttons, expect the constant BOP-BOP-BOP to drive you mad until you turn the sound off.
Nightmare Fuel: Teeth are damn creepy when you're playing this as a kid. It doesn't help that they're the only enemy that actively pursues you.
Porting Disaster: The Windows version introduced several glitches, most notably certain buttons not working consistently. Ironically, this version is the most well-known (and was pretty much the only known version until the fan program Tile World brought the Lynx version back into the limelight).
That One Level: For most players, any level that takes longer than 5 minutes. For others, a level with a time limit of under a minute is even worse. Notable examples include:
Level 33, On The Rocks. It's your first real Marathon Level, having you use a block generator to build bridges to get to tiny islands with the chips on them. It's exceedingly time-consuming because there's only a handful of generators throughout the level, and if you make one slip, you'll have to restart the level.
Level 73, Morton. You're not going to beat it if you can't trap the teeth within a spot from which it can't bother you anymore.
Level 89, Block Buster. The speed of the blocks that are replicated by the clone buttons makes them very difficult to dodge. And since Chip is a One-Hit-Point Wonder, he must never fail at dodging any of them.
Level 105, Short Circuit. A nasty maze of chip sockets and recessed walls, which forces you to memorize the layout of the maze.
Level 131, Totally Unfair, which requires you to memorize the layout of a previous level, titled Totally Fair.
Level 136, Doublemaze. It's two mazes shuffled together. There's a huge amount of chips to collect, you need every single one of them, and thanks to the level design (ice and thin walls) it's hard to tell which maze a given chip is in.
Level 147, Force Field. Mazes alone can be difficult to tackle, but this one consists of force floors that hugely increase the difficulty level. The player has to frequently overcome their motion directions to make his/her way to the chips needed to obtain the suction boots and walk directly to the exit.