A good start for a game that was made by a 7 Year Old! Only recommendation I'd have for your son because he's young is to make it a bit more interactive or skill based. A good start for him none the less :)

Woah, someone code at 7 year old. I eat sand when I was 7)

Great job Calvin! Stick with it, you can do a lot of fun stuff with Scratch and it will make it easier to understand programming languages like Python. Both my kids really enjoy it and maybe this game will encourage them to take part in a game jam :)