Employment at will.. You can get fired for no reason and you can tell them to fuck off and walk.
But like the penguin said don’t use them as a reference.
And yeah.. I have never had any sort of loyalty to a employer. They don’t care about me and I return the favor. I have walked away from tons of jobs for various reasons. They still have to pay you for hours worked. But they can’t fuck your credit or put you in jail for walking with no notice.