You can get the latest jar from the releases page.
Execute it by either double clicking or executing following command in the command line:
java -jar [file name]
You can change the speed the snake moves at by passing it as an argument:
java -jar -Dspeed=[speed] [file name]
Attention: The generated Database file will be located in the same folder as the jar. You can change the folder but make sure that both files are in the same folder while playing, otherwise a new Database file will be created!
Enter debug mode by adding an argument in the command line when executing the jar:
java -jar -Ddebug [file name]