Hi Kastriona, thank you for reporting this issue. I've asked other players who use Windows 11. All of them were able to launch the game by opening the folder and launch the exe file. I update both Itch & Steam, so they are the same version. If you still have troubles, feel free to join Dark Nights' discord. There are always people online to help: https://discord.gg/b7wwHhx
As for which platform is better, Steam takes a large cut from sales, while on Itch it's just a fee for payment processors. Dark Nights is free, so it doesn't matter on which you download. If you consider buying the DLC, getting on Itch would help me a bit more. Leaving a review on either platform would be useful for me and fellow players. Thank you so much for your thoughtfulness about creators!