The beauty of Meltdown is that even if you only have moderate speed, you can do a decent speedrun. A faster build may get to the doors faster, but due to the consistent intervals between door openings, it just means more waiting will be done at said doors. ¤(actually, there is a little more to say about this, but it is rather insignificant and I will not put it here.)

Anyways, on to describing the actual speedrunning process, which really isn't too hard to do. As far as I know, I have the fastest confirmed Meltdown time, so I guess that means I have the best strategy at the moment (by confirmed, I am including fastest time posted here, on the NK speedrun thread, as well as when compared to YouTube times). :D This is the route I took in my best run:

After completing that route, I then head down to the room beneath the control panel room and go right to the bottom right corner, where the first boss can be destroyed, then scurry up to the top left to take out the other boss and start the countdown. The last part with the boss is where the most time is lost for slower players, as they need to go from one side to the exact other side to take out the other boss, which is why I have devised the following strategy. This strategy may also work for faster players, but I have not been overly successful with it yet. As long as there is no lag, this strategy should get players with speed >50% a time under 2:45. (I have successfully completed a 2:45 run using this strategy with a 43.2% speed medic)

Method 2: Alright, so this is the second strategy, which may be more suited to slower players. The route is the same, other than the beginning, and it makes use of turrets. The second route:

As you can see, I place two turrets in the top left corner where the one boss group spawns. These two turrets are usually flame turrets and/or Zeus turrets, as they are really easy to obtain from bounties/events, so I have a lot of them. If you have turret mastery 5, you can place three turrets, though it is rather unnecessary. These turrets will use some of their ammo on zombies that come by, but that shouldn't be too many as most zombies will be following you, leaving the rest of the ammo to dispatch the boss(es).

The biggest problem I've noticed so far with this second strategy is that even though the top boss is killed quickly, there is a delay on the timer coming on, so it hasn't really made a difference on my times.

Lag is a killer in speedruns, especially on Meltdown, so beware! Always refresh before attempting a speedrun, and make sure you have everything set to it's lowest.

Well, that's my two cents on Meltdown speedrunning strategies. Good luck everyone!