Originally posted by hongducwb:

Each time group of zombie spawn, fps drop, stuttering,.....

That is strange, even old slow computers generally run the game pretty well.

What are your system specs? There might be something else going on.

I was fine until Day 13 then a few minutes ago my frame rate plummeted to around 3 fps. When I started a new game the lag remained. It was so bad I had to alt+f4 the game. The music kept playing and it still showed it as running so I had to task manager Steam.

I'm on an HP with 8.00gb ram, an amd 7770 hd and Windows 10 if that helps

Windows 10 is a real hog on performance, with those same specs you would fair much better running Windows 7. What is your resources look like in task manager before playing the game? I suspect some applications are hogging CPU and GPU resources.

Could be your integrated Video card, I'm assuming you are on a laptop.

Originally posted by InfernusMatrix:

Could be your integrated Video card, I'm assuming you are on a laptop.

Yeah, unfortunately Monogame and XNA (the tech the game is made in) do not play well with integrated video cards, especially if it's an Intel HD card (those typically don't run the game at all).