I played Agent Hunt excessively. Not because I find it so much fun to play, but just to get the final medals I'm still missing and some dog tag stars. It really gets boring and lame when you're trying to get one specific medal and the whole game is "against" you:
Not being able to play Agent Hunt with a friend. Don't ask me why, but the game constantly told me there were no players in the specific levels my friend played.
Meeting a team of superhero players. They don't even need to camp or have unlimited ammo. It's more than enough when their normal skills are leveled up and they play well. It's good for them of course but when trying to kill em it's not so funny. Especially when you can't control how or when (if ever) you transform to a specific mutation. That really puts the patience to a test.
And of course not even being able to reach a player. I encounter this especially often in Leon 3-3. I'd like to know how the game "decides" where to put you out since sometimes it's MILES away form where the players actually are.
I'd really like to get those two missing medals in Agent Hunt, but since it is mostly depending on luck then skills, i mostly gave up trying as well.