You'll do it once or twice, faithfully copying your glorious Minecraft world over to a flash drive or backup hard drive, and then you'll forget.
Everything required to run the game as well as all the content you've created as a player (game worlds and screenshots) as well as content you've added (like resource packs) is located here.
Because we focus on producing good content for you to play the game at a maximum level everything will be included.
That said, cherry picking which files to download or writing a custom batch script to do so is a bit irritating when it's just as easy to back up the entire directory (the Mojang supplied content is generally only around 200MB).
But other than that, the only way you can play Minecraft Alpha is to get the jar(most likely from the internet unless you have it saved somwhere) and replace it with your current one.
It should not create a launcher in the unity quick bar on installation, only on the desktop and in unitys menu system, the launchers that it creates executes this command.
That happened when i tried to do it on my computer at school when the school has blocked it you can not get on but you can ask you librarian or a teacher why they blocked it and why they did.
Why is it your Mods for minecraft are installed correctly and Meta file is deleted then when you run minecraft it is the same game and not affected at all and i have modloader and audio mod?
This is vanilla minecraft accessed by google drive to allow editing from multiple locations at the same time (like google drives other editors).
Also sorry to say that right now this really is only meant for straight up ubuntu with gnome, I'll be trying to get it to work with other distros and desktops in the future.