The new version requires at least .NET 8.0. You can download it from Microsoft.
You must be registered to see the links
(The Desktop Runtime is enough, you don't need the SDK)
The old version used the .NET Framework 4.8, which was automatically installed with Windows.
The new version allows us to write cleaner and more efficient code and is also the first step towards making the game officially cross-platform. I aim to have an official Linux version by the end of the year. (Also for selfish reasons, since I'll rather switch to Linux than to Windows 11 when the support for Windows 10 ends.)