I think those frontends are not updated since the original Neko Project II 0.86. Especially the SDL2 port, which didn't even include mouse support.
There is another fork of Neko Project II, NP2kai (https://github.com/AZO234/NP2kai) that supports
new features from np21w with focus on development of X11 and SDL2 frontends.
mrhso
commented
5 years ago
I think those frontends are not updated since the original Neko Project II 0.86. Especially the SDL2 port, which didn't even include mouse support. There is another fork of Neko Project II, NP2kai (https://github.com/AZO234/NP2kai) that supports new features from np21w with focus on development of X11 and SDL2 frontends.