How you can play:
Unzip the file and drop the folder inside into your Minecraft saves folder, it should then show up in your single player worlds.
You can play Disaster Star with your friends by starting a 2 hour free trial on the StickyPiston website. The server will stay up for a maximum of 2 hours, but you can immediately start another one!
If you have a Minecraft Realms subscription, you can go to the minigames tab and find Disaster Star on the list. Click it to temporarily run the game on your realm with your friends!