Unfortunately, the provided build doesn't work for me. When trying to run neverball.exe, I get an error "The procedure entry point wcscat_s could not be located in the dynamic link library msvcrt.dll." This is on a 32-bit Windows XP SP3 system.
From some short tests using my own Windows build of the SDL2-based trunk, my impression is that things generally work as expected.
Not sure about the new resolution handling, though. Tying fullscreen mode to the size of the desktop is a restriction that would bother me if I were still an active Neverball user since my desktop resolution is not identical to the resolution I'd like to play the game at. The resolution selector also lists several modes that my monitor doesn't support. I was going to blame SDL for misreporting them, but then I saw that they're actually hardcoded in st_common.c. I'm afraid I can't do any multi-monitor tests, but the one display I have was reported correctly.
As for text input, only minor issues. In the title screen, many non-alphanumeric keys (including the arrow keys) will disrupt the cheat mode activation queue when pressed. In screens using the on-screen keyboard, there's no longer a menu sound when entering characters using the actual keyboard. Intentional? Backspace, being handled differently, still beeps, though. On the plus side, the Alt+Numpad input method (e.g., Alt+0227 => ã) works now. The player name screen no longer restricts the length of the string while the score system still uses a MAXNAM of 9 – didn't check whether this actually leads to any problems.
Pressing Alt+F4 didn't close the program; turns out that WIN32 wasn't defined in my build environment. (All other #ifdefs in the code use _WIN32.) Also, is there still a valid rationale for not setting a window icon on Windows? When removing the check, the icon showed up OK with alpha intact.