NML is only about pain. Every player I know who has shot above 360, has at least broken a controller or headset.
Steve threw his headset against the wall not that long ago, Mato broke his controller, I've broken a headset, controller and TV remote in the last 3 months playing.
I can spend 2 hours not getting above 100 kills.
An hour not PAPing once.
Some caveats about that - I'm playing for very particular scores and starts, therefore it generally takes longer to get going. I can start games less frequently as in a lot of them I am wasting my time. To beat my high of 360, I can't just start any game.
Starting buzzers -
1st - running warning.
2nd - running.
3rd - grenade cooking.
4th - dogs now 3 stabs, warning for 2nd grenade.
5th - your 2nd nade has to beat this.
6th - guns in warning.
7th - 2nd single shot warning.
8th - 2nd single shot must beat this to help with the next spawn.
The 3 key points in the first 2 and a half minutes are the 3rd buzzer, the 5th and the 8th.
Let me explain a little about the 3rd buzzer.
If your nade goes off before it, the spawn after the 2nd grenade is broken.
If your nade goes off after it, but doesn't hit all zombies, the spawn after the 2nd grenade is broken.
If it goes off too long after the buzzer, the next spawn will never be 20, leading you to only kill 15 or so zombies with the 2nd grenade.
Now the 5th buzzer - if your nade goes off after this, all the zombies will pretty much be 2 stabs rather than one, and straight away you are too slow.
Any dogs you have on the PAD with you, will have had their health reset.
Now the 8th buzzer - if you shoot your single shot after this buzzer, you can and will kill the hoard most of the time, but the next spawn will be truly awful.
You have to beat the buzzer with that bullet to ensure a chance of getting a full spawn.
This spawn more than any other is my goal in any game. If I don't beat it, I generally restart. I've had too many games like this where I end up shooting somewhere between 340 and 350, but I know that from the start the game is doomed to be a 365ish max.
Some of the above isn't set in stone, but 90% of the time the game will behave as I have described.
NML is frustrating however you are - if you are just starting, its just ridiculously hard and frustrating.
The more you play, it just gets worse. I can start a game, with time to play for 2 hours and turn it off within 5 minutes.
The game is truly very glitchy, and if a few bad things happen in a row, I just quit.
Examples - knife lag from the start, back corner spawners when you are moving through the cage for your first grenade, bad dogs spawns just as you go onto the teleporter PAD (sometimes as you get up there 2 spawn in the back corner, right as well restart). Walking zombies, the list seriously goes on in ways the game can by design, bad luck or simple gameplay flaws fuck you over.
You can get 10 plus speed colas in a row, and then on every Jugg that spawns you only get 6 or 7 zombies before they start running. This can go on for 30 plus minutes where I literally don't even get a chance at a game.
On the other hand you can have an hour session whereas I PAP everytime, the spawns are all really big, and in an hour I've gotten 4 or 5 350 plus games.
I both love and hate NML, as do most people