I dont know what is causing this but anytime I leave the starting town and go out into the desert my game slows down considerably. Even though my computer is much more than capable of running the game. My directx and my framework are both updated with the newest versions. I cant figure out what is causing the problem.
Do you use a mouse or something else from Razer? If you do try to unplug ist and see if it works better. Had the same problem with my mouse. As soon as I unpluged it the game was running smooth.
There's a known bug with the engine that slows the game down if you use a different controller (or unplug one). This is a Game Maker issue, and unfortunately can't be 'fixed' by the devs. If you have connected a gamepad to the computer, keep it connected during play. You may even have to plug in more than one controller if they've both been connected to your computer before. If you want to keep a controller unplugged, you'll want to restart the computer before playing or the engine will continue to try and find that controller. If you want to use keyboard controls, while having a controller plugged in you can use F1 to toggle. Some razer mice/keyboards can be confused for controllers as well.