I found a way to play Nuclear Throne mods on mac, but you'll still need a pc (sorry if i do a trash job at explaining it :P)
On your PC you'll have to get to the games local files and drag everything to a flash drive. Right after, eject your flash drive and put it in your Mac. Then you'll have to install Wine. Right after you install Wine, put all the files from your flash drive into a folder. Finally, drag all the contents of Nuclear Throne Ultra into the folder then right click the Ultra exe and open it with Wine.