BSaST circles collision detection? -- then:

[earthbound19]

(break these into new issues if you do them)

• contacting circles bouncing via correct physics of contacted vectors?
• different collision detection for squares, triangles, if those are added (add circles collisions first)

[earthbound19]

Moved to Trello card; under consideration: https://trello.com/c/FIIz3qzd/103-bsast-transparent-bg-option