How to open Minecraft in Ubuntu?

I successfully downloaded the launcher for Minecraft. However, after I click 'play', the launcher closes and then it opens the launcher again. How do I fix this? Please help!
I'm running Ubuntu 14.04 (xfce4) and I have Java.

I think another think you need to look into is if Minecraft work on Linux. Unbuntu is a Linux-based OS

>>Easily Install Minecraft on Ubuntu<<

Step 1 - Files/Programs
Go to the Ubuntu Software Center and install OpenJDK Java 6…
Get minecraft.jar from here and place in you home directory.
Get minecraft.svg from the attachments at the bottom of this post and put it in the same place.

Step 2 - Terminal
Open the terminal and type: sudo bash
Enter your password (not the root one)
Then type: ls
Check if the files you added are there.
If they are type: chmod a+x minecraft.jar
This will make it run-able
Close the terminal

Step 3 - Open with
Go to the minecraft.jar file and right-click on it
Select preferences and set it to open with OpenJDK Java 6…

Step 4 - Launcher
Add a launcher on the desktop (right-click)
Click on the image and locate minecraft.svg
Name it Minecraft
Set the location as the minecraft.jar file