Hit 'See inside' to open the code, where I have written out the code as well as notes on what each block does! No variables are needed. ------ Hit 'Space' to look at and change the speed of the bubbles! Default speed is 3 :)
If you copy the code, or use this for reference, please mention me in 'Notes and Credits' And also be sure to let me know either in the comments of this project or under my profile as I would LOVE to see the project <3