What Typical VVVVVV Obstacles do you struggle with the most?

[Flushex]

Narrow paths, like 2-tile-wide pits with spikes on both sides, corridors when you must tap precisely to avoid spikes, etc.

I find veni vidi vici tunnels mostly pretty easy. There's one exception though (Yes Golden Spiral, I'm looking at *you*)

The first trinket in Golden Spiral is clearly ridiculous. Even Rox himself has to admit he wasn't able to do it.

[Pyrite]

Also, the shock panels everyone makes with scripting. 

I've only seen them once in CCCCCCCCCC.

Roskilla used them in WWW and they're horrifying.

[Dav999]

The first time they were used, they were original. Then, it was copied like 3 times by other people.

[ToasterApocalypse]

The first time they were used, they were original. Then, it was copied like 3 times by other people.

Arrg... copiers.

I struggled with rooms that have enemies that go like

>O                     
                                 O<

Which is pretty dumb because I used those 

[Flushex]

The first time they were used, they were original. Then, it was copied like 3 times by other people.

Arrg... copiers.

I struggled with rooms that have enemies that go like

>O                     
                                 O<

Which is pretty dumb because I used those 

Slap on some gravity lines above and below those enemies and it's even harder.

[blue626]

I also found the challenge mentioned in the 1st post hard.

I believe that the first time the shock panels were used were in "Soul Seaching" by Martze (I didn't play it yet) and then were used in other levels by other people (some of them I didn't play) like This is Portal by PJ, CCCCCCCCCC Retold by Whirligig, The Long Adventure  (or something...) by Piplup and D. WWW by Roskilla.

2-tile-wide pits with spikes on both sides

I only find those challenges hard when you flip form a conveyor. The hardest case is probably in "Dual Challenge" by Souleye, where there were 2 conveyors touching each other, one going to the left, the next one to the right ( had to go right and then up through the tunnel) and the division between the 2 conveyors was right in the place where you have to flip! There's also an enemy that goes in and out of the tunnel! At least the lower spike in the left side was more to the left than the others!

About DTTHW tunnels, I think that they have medium difficulty. I didn't try the one in Golden Spiral, though (I skipped it).

EDIT: I think that the ones that have both horizontally and vertically moving enemies in an open area (in only one room) are hard, specially if the horizonatl ones are on the floor and ceiling or if there are grav. lines instead of floor and ceiling. I've seen these in D. WWWWWW as well as in other levels. The challenges that make you flip a lot (like the WWWWWW challenge in D. WWWWWW and the next room, "Tourist Trap") are also hard.

[Flushex]

To me, conveyor challenges are only hard in areas where they are constantly changing direction, like you said. Otherwise all you have to do is stand still and flip at the right time, which is easy even in the case of the narrow >|_|_|< gaps.