Didn’t really need to delete your post and repost the reply, since a reply it a reply in a thread regardless of if you reply specifically to me 
(epsecially in a thread of just two people)
Yes you can do these sort of games, but no you can’t have them controlled by keyboard.
Extensions using keyboard may stops regular access keys working or could interfere with the player pause/play if you were using spacebar as a shortcut. This this leads to user/viewer comfusion (and theres no keyboard per sae for users on platforms that don’t have easy access to keyboard, such as console, tv, or mobile.
So TLDR:
- yes you can make games
- no you can’t use keyboard as a game controller.