Mac Crashed

I had bought Minecraft, and downloaded the Launcher. I then moved it into the applications folder on my Mac, as you should. It then asked me if I wanted to replace an app with the same name (I had the demo version downloaded) and so I selected yes. I went through the set-up as normal and then pressed play. Eventually it came up, but the menu was in pirate English. As well as this, I couldn't click on anything. I eventually managed to go to the world screen, which showed the demo world as the only world. I then selected to make a new world, and the app then froze up. I switched back to the desktop (I had put it on full screen) and attempted to force quit the application. It didn't quit, and I found myself unable to press any buttons on the top bar. I would click them, and nothing would happen. It would register it as well, as the menu would close as if I had properly clicked it, and yet nothing would happen. I finally resorted to a hard reset by holding down the power button, and after computer had trouble turning on. It then worked fine, so I came here for help.

Also if you are wondering I have 8 GB of RAM.