Mars Attack - Making a game with retro sprites in 10 steps

Hello again,

I implemented another mini game using p5.js / p5.play and in-code defined sprites (e.g. text format) on the codeguppy.com platform.

The game is still basic, however I didn't construct the game to be a polished game, but instead teach various game building techniques.

This is the game

https://codeguppy.com/run.html?mars_attack/program

And this is how it was made:

Part 1 - Generating mountains from random lines
https://codeguppy.com/code.html?mars_attack/mountains

Part 2 - Adding a landing ramp at the end
https://codeguppy.com/code.html?mars_attack/mountains2

Part 3 - Solid mountains, Stars and Stop at Ramp
https://codeguppy.com/code.html?mars_attack/mountains3

Part 4 - Adding player ship using in-code defined sprites
https://codeguppy.com/code.html?mars_attack/mountains4

Part 5 - Adding enemy, collisions with enemy
https://codeguppy.com/code.html?mars_attack/mountains5 

Part 6 - Tune scrolling speed. Scroll faster when accelerating
https://codeguppy.com/code.html?mars_attack/mountains6 

Part 7 - Ship shoots rockets
https://codeguppy.com/code.html?mars_attack/mountains7 

Part 8 - Adding explosions. Ship can now land!
https://codeguppy.com/code.html?mars_attack/mountains8

Part 9 - Ability to restart the game
https://codeguppy.com/code.html?mars_attack/mountains9

Part 10 - Adding intro screen. Option to collide with mountains
https://codeguppy.com/code.html?mars_attack/mountains10

Comments welcomed!