I'm not sure why, but when I run this game, I get lag or stuttering problems. Does anything know of a solution to this?

It happens, but normally, it vanishes while you play. Load a save and go in some rooms before starting a run, it can help =).

~MetalFox Dioxymore

Try to higher the priority in taskmanager while it's open. It helped for me when I needed it.

(set it on higher than normal or high, but not realtime(ignore the german =P))

Also what Dioxymore said, loading a save before starting the real run helps too.

Thank you for your help, Dioxymore and Dacciox.

I've tried reinstalling onto my SSD, changing my computer from Balanced to High Power Mode. Changing resolutions and even reinstalling my video card drivers.

I raised the priority on Teslagrad and it seems to be working a lot better. Thank you very much!