Some changes are obvious. The switch port uses very aggressive change solutions, leaving the game as little as 640 x 360, even when you support the system. This is a game that is best played in handheld mode. Panic button also deleted the 30FPS target frame, reduced texture quality, and produced noticeably simpler waterproof effects without reflections and 3D interaction.
However, other changes are subtle. While the game is intact, there are minor changes in the environment to maintain performance (such as inserting a wall to block an extremely detailed background). Volumetric lighting and shadow are not quiet as detailed either. And in some cases there are improvements in performance. The frame rate is usually more consistent than it is on regular PS4 and Xbox consoles (not to mention the previous Doom release on Switch) while the cutscenes start before.
All told, The Wolfenstein II Switch Version is not going to be as superficially impressive as it is elsewhere. Panic button made a number of compromises and you should notice them. Nevertheless, it is a testament to the Switch's relative power that Panic Button should not resort to more drastic measures, such as cutting the levels into smaller pieces or noticeably simplifying the geometry. You can play the game largely like Bethesda, MachineGames and ID originally intended ̵