It can also be used as a verb to describe putting a lot of effort into something and fretting over the minor details of it.
"God, I just got pwned by a bunch of tryhards."
"I'm going to tryhard the fuck out of this assignment so I don't fail this class!"
Try Hard #2; Ohh i got a 98, i had to go to the nurse's office i was crying to hard. when i get home i'm going to rewrite that paper on quantum mechanics and how time travel is immp-----
Normal Kid; You are both Try-Hards shut the hell up. jesus your all really fucking annoying.
Intelligent Student: Just a moderate amount of time, an hour or so, but I got a A-, so I'm satisfied.
Try Hard: What!? I studied for four hours and made a C+!