Checkpoint 1:  https://makecode.com/_YLDcVW7rWX0Y 

Checkpoint 2: https://makecode.com/_dMKD7mL6WLqC 

Checkpoint 3: https://makecode.com/_bcrJKhE1tKVK 

Final project: 

https://makecode.com/_c6DH63WX15eA