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The remaster or whatever you call it, I open it up and it goes straight to fullscreen. I've checked controls/options, and there's no option about getting out of full screen.

Is a windowed mode even possible with this new version, or does it need a workaround?
This question / problem has been solved by zenmachinegunimage
ALT+Enter will window it but the window itself is not resizeable. From what I understand when the HD version launched on Steam a few years ago is that the engine they used for this version prevents them from easily implementing the feature without breaking everything. The best the devs seemed to muster was adding in support for more esoteric default resolutions and that's it.