The most frustrating part of the game...
 

...was looking for the can. As a fan of the film, I knew exactly where to look for it, but Nima couldn't find it until all steps of that chapter were completed! ;)

Mine was actually the Bone Shaker Puzzle. The Puzzle itself was easy, but finding out you could fit four cars on the track and not just three wasn't. lol

Mine was the QTE. ARGH! UGH.

Some of it was well paced but more of it frustrated the heck outta me.

Mine would be not remembering that I had to wait for the arrow button to pulse, and not press ON the pulse when throwing the rock to turn the electricity on at the bone shaker.

Also creeping up on the T-Rex was a pain!

This.

Mine was blinking.

Mine was trying to figure out the order at the Marine Facility.

Lol, that bothered me a little too. Same when Billy and Nima were in the tunnels and he went over to the fuse box, and the game made me do the exact opposite of how I knew the switchbox worked. I was like, "Oh, I recognize this." *clicks on primer handle* Billy: "WTF is this crap?" *facepalm, clicks "Push to Close"* Billy: "Close what?!" *head-desk, apprehensively clicks "Push to Open"* Billy: "Yeah, open, that HAS to be it!"

HERP DERP!!!

Definitely the Yoder knife fight, at least it was the most frustrating to get Gold in. Man, I must of watched the opening sequence 40 times to get through the fight perfect...

...was when it was meant to hold the RB and press an additional button but it just displayed "RB" first.
It took several trys to find out that I shouldn't just tab RB shortly....

Yeah, man. This might be the first game I get EVERY XBL Achievement for, but that particular one is maddening. I only need 3 Achievements, doing that perfectly, doing the escape from T-Rex at the docks, and Survive the whole game. Surviving isn't near as hard as getting a perfect and after playing the whole game (more than once), I'd have to agree that this is, by far, the hardest QTE to perfect. There are a few parts where it requires you to hit multiple buttons in quick succession, and the timing window is smaller than a lot of the other QTEs in the game.

I'm having a very hard time getting gold with the Nima vs. Yoder fight.

The ones that really infuriate me are whenever I have to painfully wait for the green marker to get inside the button prompt for me not to fail the sequence (jungle slashing, sneaking around, etc).

There are others that have me grinding my teeth, but those's are first thing that comes to mind when I think frustrating.

the fight against billy, i have yet to get a medal in the fight.