Hey I tested Ubuntu KDE. The error I had:
unable to preload the following plugins:
ScreenSelector.so
Player data archive not found at `/home/user/Descargas/Cubito - Linux x86 Version/Cubito_Data/data.unity3d`, using local filesystem
Beside it runs well through the menus but I haven't been able to see the arena or anything. Then menu didn't work and then I xkilleduname -a
Linux 4.8.0-59-generic #64-Ubuntu SMP Thu Jun 29 19:38:34 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux