Nice game, I was surprised how short the actual program was!
I wrote up some comments on your code which is here
https://pastebin.com/yz04DK7eand a modified version demonstrating what changes I'm talking about
can be found here
https://pastebin.com/he0RFX0mThe modified version is still glitchy, but I hope you can learn something from it.
The biggest problem with your code is the drawing function. Computercraft can't draw fast
enough, and by drawing the whole screen every time you get a game that is very flickery.
For games it is much better to change things character by character instead of just
printing out the whole screen every time.
Some suggestions for improved versions would be starting the ball from a random direction
and in a random location, improving the brick breaking mechanics, and perhaps changing
the direction of the ball based on where the ball hits the paddle to give the player a little more control.
